I have a number of new Mercedes ML Series Trip Computers A163 540 52 11 I have sold on eBay with instructions on how to install it yourself in any ML that didn't come from the factory with one . Although they can also replace any defective unit that did come with one. To view a tour of the functions of the overhead onboard computer go to this link
formatting link
you would like a 620 kb email with adobe instructions on how to installthe unit please feel free to email me at snipped-for-privacy@kc.rr.comThanks!