Painter's tape would work as well.
I'm just being careful around my exposed fenders. They will get a nice compound and polish once the car is running again. Fender covers get dirty too quickly from what I've seen - I would definitely never want a shop to use them unless they are brand new.
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2011 370Z 6MT Sport Gun Metallic | ARC | CJM | Ecutek | FI | Fujimura | R2C | SPL | Stillen | TWM | Z1 | ZSpeed | |