sparks and spare time.
Thanks for the fast reply, I was already worried about possible damage.
If the risk is that I fry a coil, expensive enough, I think that I wil have time very soon to change the sparks back to the non resistor ones.
The stupid thing is that Bosch promotes the R ones, at least these ones, for my car and says that these are the new stock plugs for mercedes. I will ak my local Benz shop.
Thanks again and have fun,