I don't know if anybody actually does this the way we are supposed to, but the way I read the legal gibberish, switching from the Standard Mileage Rate to Actual Expenses gets a bit funky.

By using the Standard Mileage Rate in the first year, you have elected out of MACRS (§168).  And you aren't allowed back in.  So you should actually then depreciate it using §167, which means you depreciate it over the "useful life" (I think pre-MARCS said it was 3 years, rather than the 5 year the Recovery Period) and using a "Salvage Value".

But again, I don't know if anybody actually does that.  😂