TT failed to correctly carry over 2021 information for my vehicle, leaving unchecked "For post 9/27/17, elect 50% in place of 100% Special Depreciation Allowance" (Car & Truck Wks line 36a - 2). The bug probably occurred because last year the vehicle was <50% business use, so it was not relevant, but this year >50% use, but TT skipped the relevant questions on step-by-step. So, I checked "no". However, I noticed that if I uncheck "Economic Stimulus - Qualified Property" (line 36a) my depreciation deduction actually increases. This seems odd. Is it permissible to uncheck this for a vehicle (A1 auto placed in service 2021, mixed personal/business)? And why would the depreciation be higher without the special depreciation? I can't see the underlying math.
