Old Auto on tax return and books entered at 100% $30K, Depreciation taken over years at 80% is $21K, it is Old Auto traded for new auto in 2022

2022 trade in for new auto amount of trade in $16K, Cash paid after trade in $32K, total paid for new business vehicle $48K

On Proseries Asset entry worksheet entered $16K as Asset Sales Price, that amount is being questioned. 

Form 4797 shows sales price $16K, 80% of $30K is $24K, Depreciation allowed (at 80%) $21K, Adjusted basis $3K ($24K less $21K) Total Gain = $13K ($16K trade in minus adjusted basis $3K) 

Value of new business auto on tax return and books $32K + $16K = $48K which is total purchase price of auto on auto purchase agreement, that new auto price is depreciated at 80% business use. 

Should Asset Sales Price on Proseries be trade in amount at $16K same as on auto purchase agreement or reduce to 80% $12,800, thus reducing new vehicle value on tax return and that amount will not equal Auto Purchase Agreement