If I recall correctly, Tyson’s Mercedes will stop service on smarts in a couple years. At least that’s what I was told by another dealer.
You may not get a reply any time soon. Matt_453 has not been active for just over three years. The "service flap" on the 451 refers to the front opening. I am pretty sure it means the same thing on a 453.When you say “service flap”, you mean the front hood or the one in the trunk where the engine is?