how many used cars were sold in the united states in each of the past
couple of years and what percent were financed vs. bought without
financing.   please give sources

Sometimes the buyer arranges his own finacing; credit union, bank,
relative, friend or loan company. Often they put part of it on their
credit cards either directly or indirectly. Some of these will be
unknown to the seller, and difficult to identify. Do you want to
pretend all the above (credit union bank, etc.) are cash? Is seller
finaning and seller arranged finacing sufficient for your needs? Can
we egnore both cash and credit deals between private parties = no
dealer envolved?  Neil