[bardworx]

https://repairpal.com/reliability/mercedes-benz

I'm not sure how reliable this site is but in general, it is accepted that most luxury German cars have reoccurring issues. The reason why I say "accepted" is because in most cases, they are pushing cutting edge technology and with so many parts, something is going to give.

I do not know common Mercedes issues but with BMW SUVs the most common issues are plastic parts near gaskets (leaks), electrical systems, and ventilation (especially in X3).

Of coarse there are exceptions and not all cars are created equal but this seems to be the consensus year after year.