A college student is buying a new subcompact car which costs $$26000$ plus $8\%$ sales tax. The title, license and registration fees are $$1500.$The dealer offers her a financing program that starts with a monthly payment of $$200,$ and each successive payment will increase by a constant dollar amount $X$.$ The dealer offers to finance $85\%$ of the car's price, taxes and fees for $48$ months at a nominal interest rate of $9\%$ per year compounded monthly.

How much is the constant dollar increase $X$?$

How much is the last payment?