Hello. I'm new on here, I have a stupid question. I have a 190e 2.0 and was looking to buy a 2.6 from off a web site, the seller has posted some picture and I notice a 1 inch square plastic in the speedometer, It looks like some sort of computer display. this is not on my model and was wondering if anyone can tell me what it is, I looks like the system checker thats fitted to audis but the haynes manual doesn't mention that merc uses these. I would ask the seller but he is very slow in returning email and I dont want to wait untill the sale end.