I've got 18" alloys on, should I change the wheels back to the original Skoda ones for Skoda servicing?

It may cause warranty issues if a bush etc needed changing?

It's the only thing that's modified on the car...

if you don't want them damaging , then yes , remove them

I would say yes. No doubt there will be some dealers who would blame a fault on wrong wheels :rotz: Any excuse and all that

I have never had any problems with mine at the dealers, when they said about replacing the console bushes they never said anything about the coilovers or wheels.

I personally would just leave them on

Different car and all, but my previous car was under warranty and I had work done with aftermarket alloys... idea of taking them off never even crossed my mind tbh.

There's no need to.

I left mine on bu then again they were newly refurbed spiders with new tyres. The dealership didn't mind them

I think you should be ok with them still on the car but take a picture of your wheels before you hand it over and when you pick it up make sure they have not been kerbed when going on for the test drive that the mechanics seem to do.

The only time a dealer's eye brow will rise, is if a mod is likely to cause any damage or give them a get out of warranty claims (ie suspension, maps, brakes etc).