You dont have an OVP your car is too new. Check the cap and rotor for cracks moisture and buildup. Put the right plugs in Bosch F8DC4's, they are non resistor plugs copper core. They are the closest thing you can get to the right plug. Overseas uses an even hotter plug but cant seem to get them here in the states so i am told.

I would check you A/C charge and/or the sensor as that kicks your fans on low speed.

Coil paks are a really good idea to replace. I am sure they have been on there since you have owned the car, my cars were original when I got them. Plastic covers just kinda keep them out of sight out of mind.

Might check fuel pump/pumps and the filter and check valve just in case as it could be pressure related. Run some chevron through they use a little more detergent in the gas.

Your EHA/ETA could be an issue as our cars are "fly by wire" and its all electrical. If you go to benzworld.com and look up rewiring them youll see they suffer from the same wiring issues as the wiring harnesses.

Good luck hope that helps, tried to go cheap to expensive; small to big deal.