Take a look at section 280F depreciation limits also known as Luxury Auto limits. Per quickfinder depreciation book, when depreciation is limited due to the section 280F limits, a vehicle will have unrecovered basis at the end of the recovery period. This basis can be depreciated until the car's full depreciable basis is recovered (assuming the vehicle continues to be used for business..... you can read the rest for yourself in the depreciation quickfinder handbook. It is great.