Just purchased a 2007 S550 4 Matic with LOW miles (5200). Since the car was rarely driven, what items should I pay particular attention to in order to determine overall condition? Car is heavily optioned and was an early delivery (August 2006). So far I have suspect batteries and tires. Any other items that I should be looking at? I'm a new member but have perused the board for the last couple of years....very informative! Thanks for your help.