Ok my 2009 CLK 350 had a run in with a curb and now I need a new tire. The question is when getting the tire the shop said there are 2 types of Continental ContiSport Contact 3's and one says MO, is the MO (Mercedes Only) necessary?

 

Your replacement tire should be the exact same as the one you're replacing. If the other three are MO, you should get an MO.