Hello just leased a 250IS a week ago with 10K miles per year, for 4 years. Got a base with 18" wheels. It will be used for going to work, so didn't want it with any option. My buy out value will be 18K. My question is if I want to buy the car, do i have to take it to a Lexus dealer? Also if I go over few K's how flexible is Lexus when it come to Lexus when returning there leased cars?