You have saved $$4,000$ for a down payment on a new car. The largest monthly payment you can afford is $$300.$ The loan will have a $12\%$ APR based on end$-$of$-$month payments.

a$.$ What is the most expensive car you can afford if you finance it for $48$ months? Do not round intermediate calculations. Round your answer to the nearest cent. $ $$

b$.$ What is the most expensive car you can afford if you finance it for $60$ months? Do not round intermediate calculations. Round your answer to the nearest cent. $ $$