Converting a business asset in a sole proprietorship to personal use isn't a taxable event. However, your basis in the car is reduced by "depreciation" in the event it is sold.
one way to deal with any sale is to split the $44K cost based on % business use for all the years it was used in business. a way to do this is based on business mileage to total mileage. the other portion of the $44K would be personal.
you would prorate the sales price using the same %'s (the $30K current FMV is meaningless)
business portion
from the business portion of the cost, you would subtract the depreciation taken to arrive at the adjusted basis - never below zero.
business portion of the sales price - tax basis is the gain which is ordinary income (section 1245 recapture) to the extent of depreciation any excess is capital gain
personal portion
personal portion of the sales price - personal portion of the original cost is a gain or loss. any loss is a nondeductible personal loss while any gain would be long-term capital gain
gain
