I usually go to my local car wash, they use a jet washer. I have just ordered my cactus and heard about white marks appearing on the airbumps? Is it safe to still visit my local car wash or shall I clean it myself?
Depending on what model you have you shouldn't use a high pressure jet because of the front and rear parking sensors, if fitted. To be on the safe side I use my own pressure washer on low and have no problem with the air bumps.
Perhaps someone had a bad experience with getting white wax polish on them which might get into the texture of the surface giving it that white fleck look, like you see on badly polished cars where its on the door handles an whatnot.
I don't know why people use pressure washers anyway, I've always found you can point them at dirt film and nothing happens but it wipes away with your finger! It's all down to the detergent you use I guess.