1) It largely boils down to intent of the so-called "gifts". From my perspective, you traded your car for your mom's old car. So actually your 'sale' price could be the Fair Market Value of your mom's car at that time.
2) Amy mentions nothing about different calculations about gain versus loss (in her example, she even implied you could take a deductible loss based on the purchase price, rather than the FMV at conversion to business use). She mentions nothing about treating the business portion separately from the personal portion. Both of which I gave you IRS links to support.
