I had vehicle writeoffs in excess of 100k and the depreciation is causing me to owe, I now have 2 days to reply to an exam letter after no help from turbo tax audit defense and had to go on my own. The irs rules I beleive should be different for commercial vehciles since I used a freighliner chassis rv to pull a 38k pound trailer but they are not letting me claim full or even half depreciation like I did per the turbo tax filing algorithm
we can't see the iRS notice and therefore do we know the reason it provided for limiting the depreciation.
we also don't know why Audit Defense was unable to assist you. at this point, you may need a tax pro. if anyone will take this at such a late date. if you do nothing you will owe the tax bill. you may need the pro to look over what was entered in Turbotax. if you made correct entries and there was a miscalculation you can file a claim to recoup penalties and interest. if you made errors in entering the info, Turbotax is not responsible.