A strong study with an asterisk no one mentions
Physically, a dealership is a cost seg natural. The showroom is finish-heavy by franchise mandate: feature floors, display lighting, branded interior elements. The service department is an industrial shop: lifts, compressed air, exhaust extraction, lube distribution, alignment equipment, and the electrical serving all of it. And the lot, often the majority of the parcel, is 15-year paving, lighting, and fencing at inventory scale. Engineered Tax Services reports 29% to 35% typical acceleration for dealerships, a tight, dependable band.
The asterisk is statutory. Dealers finance inventory with floor plan debt, and the interest rules give floor plan financing interest a full deduction outside the Section 163(j) business interest limitation. But the statute pairs that relief with a cost: a trade or business that takes the floor plan exception (because its interest would otherwise be limited) is excluded from bonus depreciation for that year. Whether your dealership actually needs the exception in a given year is therefore a threshold question that changes the entire study model.
This page covers the property profile first, then the floor plan analysis, then the planning that reconciles them, including the real estate entity structures that can keep the building's depreciation outside the dealership's limitation.
If the dealership's own interest profile forces reliance on the floor plan exception, bonus depreciation may be off the table for that trade or business that year, and the study's value shifts to accelerated MACRS lives instead. If the exception is not needed, full bonus applies. The financing facts drive the depreciation model, so compute them first.
The Dealership Component Map
Showroom, service, parts, and the lot.
| Component | MACRS life | Notes |
|---|---|---|
| Showroom feature flooring, display lighting, branded elements | 5-year | Franchise image finishes distinct from shell |
| Vehicle lifts, alignment racks, and their anchoring | 5-year | Service equipment |
| Compressed air, lube distribution, exhaust extraction systems | 5-year | Shop utility systems serving equipment |
| Parts storage racking and mezzanine shelving systems | 5- or 7-year | Movable storage systems; structural mezzanines are building |
| Dedicated electrical serving shop equipment | 5-year | Allocated share of distribution |
| F&I office millwork, customer lounge builds, service drive finishes | 5-year | Interior fit-out layers |
| Lot paving, striping, lot lighting, fencing, display pads | 15-year | Often the largest pool on the parcel |
| Monument and pylon sign structures | 15-year | Site improvements; electronic sign faces lean 5-year |
| Showroom shell, service building structure, core systems | 39-year | The buildings themselves |
Franchise image programs periodically mandate showroom refreshes; each cycle is new fit-out property plus dispositions of the prior image package when component records exist.
Worked example (illustrative)
Franchised dealership campus, $11M construction (real estate LLC)
- Construction cost (excluding land)
- $11,000,000
- 5-year: showroom finishes, shop systems, fit-out
- $2,100,000
- 15-year: lot paving, lighting, signage, site
- $1,450,000
- Total accelerated (32.3% of basis)
- $3,550,000
- Year 1 if bonus applies to this trade or business
- ~$3,550,000 plus straight-line
- Year 1 if bonus is excluded (floor plan exception used)
- Accelerated MACRS on 5/15-year pools instead
Illustrative round numbers within the ETS 29-35% range. The two bottom rows are the same study under the two financing outcomes; even without bonus, moving $3.55M from 39-year to 5- and 15-year MACRS is a substantial win.
The Floor Plan Financing Analysis
The threshold question dealership depreciation planning starts with.
Section 163(j) limits business interest deductions for larger taxpayers, but floor plan financing interest is deductible in full for a qualifying dealership trade or business. The trade-off sits in Section 168(k)(9)(B): property used in a trade or business that has had floor plan financing indebtedness is excluded from bonus depreciation if the floor plan interest exception was taken into account, that is, if the business needed the exception to fully deduct its interest that year.
The practical analysis runs year by year: compute the dealership's interest limitation as if the exception did not exist. If all interest (including floor plan) would be deductible under the general 163(j) limitation anyway, the exception is not taken into account and bonus depreciation remains available. If the limitation would bite without the exception, the exception applies and bonus is excluded for that trade or business that year. Rate environments, inventory levels, and profitability all move this answer, which is why it must be computed on actual numbers, not assumed.
Structure adds a planning layer: dealership real estate commonly sits in a separate LLC renting to the dealership. An electing real property trade or business, or a rental activity analyzed on its own facts, may sit outside the dealership's floor plan limitation, though real property trades electing out of 163(j) take ADS lives on their real property, which interacts with the study. These structural choices are genuinely technical, interact with the self-rental rules, and deserve individual analysis before the study is scoped.
Hypothetical case study
The dealer whose answer changed with interest rates
This is a hypothetical, illustrative composite, not an actual client or an actual result. Savings vary with your income, entity, state, and how usable the losses are.
A hypothetical dealer built an $11M facility during a low-rate year: floor plan interest was modest, the general 163(j) limitation covered everything, the exception was not needed, and the study's $3.55M reclassification took full bonus in the placed-in-service year.
Two years later, in this hypothetical, higher rates tripled floor plan interest and the exception became necessary, excluding that year's new equipment purchases from bonus in the dealership entity. Purchases were instead expensed under Section 179 where eligible, and the real estate LLC's subsequent lot expansion, analyzed as its own activity, was modeled separately.
Hypothetical composite, not client figures. The point: the bonus answer is annual, not permanent, and each year's capital plan should be routed through the current computation.
The Dealer's Broader Stack
Image programs, entity design, and the service department's economics.
- Facility image programs: manufacturer-mandated refreshes are recurring capital events; sequence each with dispositions of the prior package and the current-year bonus/179 analysis.
- Section 179 as the bonus alternative: 179 expensing is not subject to the floor plan exclusion, making it the primary tool for equipment in exception years, within its limits.
- Real estate LLC design: lease rates, the self-rental rules, grouping, and the 163(j) posture of each entity are one integrated design, not four separate questions.
- Service equipment refresh cycles (lifts, alignment, EV charging infrastructure) are recurring deduction events; EV infrastructure may also carry credits worth screening.
- Look-back studies on long-held dealership campuses, with the catch-up year chosen against the floor plan computation.
- Succession and buy-sell planning: dealership real estate held separately from the franchise is the classic family-transition asset; our business succession planning guide covers the framework.
Taxstra Tip
Route every year's capital budget through the 163(j)/floor plan computation in Q4, before purchases close. Whether bonus, 179, or straight MACRS is the right tool for that year's spend is knowable in advance, and the answer sometimes argues for moving a purchase across year-end.
Delivering Dealership Engagements
Financing analysis, engineering, and the return, in the right order.
We run the floor plan and entity analysis first, coordinate the engineering through Engineered Tax Services, and model the study under your actual bonus posture. Taxstra implements the schedules, the image-program dispositions, Form 3115 catch-ups, and the annual capital-budget routing.
Disclosure: Taxstra may receive a referral fee if you engage ETS through links on this page.
Estimate Your Savings
A quick estimate from the ETS calculator, then a study only if the numbers justify it.
Estimate Your Cost Segregation Savings
Run your property through the Engineered Tax Services savings calculator for a quick estimate, then have Taxstra pressure-test the number against your full tax picture.
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Calculator provided by Engineered Tax Services. Estimates are educational only and depend on an engineering-based study of your specific property; results are not individualized tax advice.
Disclosure: Taxstra may receive a referral fee if you engage Engineered Tax Services through links on this page. That relationship does not change your price, and it is not a recommendation for your specific situation.
See What a Study Could Do for Your Property
Engineered Tax Services performs the engineering-based study. Taxstra turns the report into actual tax savings on your return and coordinates the strategy around it. Start with their calculator or real case studies.
Want proof first? See real client case studies from ETS with the numbers behind each study.
Disclosure: Taxstra may receive a referral fee if you engage Engineered Tax Services through links on this page. That relationship does not change your price, and it is not a recommendation for your specific situation.
What to check before you order a study
The pre-study review that decides whether the deduction is actually usable.
Compute the 163(j)/floor plan posture for the current year before modeling the study.
Confirm which entity owns the real estate and how its interest and elections sit.
Inventory manufacturer image program requirements and their calendar.
Scope the study to capture showroom fit-out at component level for future image cycles.
Screen EV charging infrastructure plans for credits alongside depreciation.
Model both bonus and no-bonus scenarios in the cost segregation estimator.