Investors & landlords

This is confusing. Can you tell me if my MANUAL calculations below are the correct formula?

(And then I can use Turbotax to generate the same result).

 

I bought the car in 2010 for $2500.

I sold it March 29, 2023 for $400. (junkyard sale).

I have $1600 in depreciation 2010 to 2023 (based on depreciation portion of standard mileage deduction).

I used the vehicle about 20% for my rental property (on average). So, 80% of usage is personal use.

 

Is my 'cost basis' 20% of $2500? (ie: $500 ?)

Is my 'sale price basis' 20% of 400? (ie: $100 ?)

Do I subtract my cost basis from (selling price + depreciation) to arrive at gain or loss? (500 - (100 + 1600) ) ?

Do I have a income gain, or loss, for tax reporting? (Is it  -$1200  loss, or gain?)

 

I think if i understand WHY I am doing all these calculations, it would help me understand the TT forms. Thanks!