if you look closely at your wheel bolts, the part that you can see is actually a plastic cover - like the ones in the picture below. The hex bolt shape is only in the very front edge of the cover - behind that it’s cylindrical, so it would be very difficult - if not impossible - to fit a wheel brace on to remove the wheel. There is also a recessed ridge behind the hex shape to fit the bolt cover removal tool (a bit like a large pair of tweezers). You see this better from the pictures below - from the forum sponsor’s website (
@COX Motor Parts) - click on the thumbnail images to enlarge them.
I was under the impression that all wheel bolt covers on Seat and Cupra cars were black (maybe not?) when the painted parts of the alloys were black. The discussion thread at the link below contains an image of a
Seat Tarraco‘s wheel bolt covers that have discoloured / faded and they look quite similar to yours (car has been washed at one of the many hand wash car washing places).
www.tarracoforums.co.uk
You've not said in your earlier posts if you purchased your car new or used. If the latter, then as said in my earlier posts, an unsuitable cleaning product may have been used that has caused the fading / marbling effect on the bolt covers and has also contributed to the corrosion on your hubs. Many of the hand car wash places use very harsh (and IMHO, unsuitable) cleaning products to remove dirt quickly form customer’s vehicles to speed up the throughput of vehicles; the more cars they can clean, the more money they earn. Therefore, if you‘re not the original owner of your car, it may have been subjected to being cleaned at one of those hand car washing places, which could’ve caused your
problem. The Cupra dealership you bought your car from may have used similar products when preparing your car for sale, although IMHO that’s less likely. They may have used a plastic dressing product though to hide any discolouration / marbling on the plastic bolt covers.
I can understand your annoyance and frustration. However, in your position, if your corroded hubs are the only thing that’s causing you annoyance and frustration with your car, I’d remove the corrosion, repaint the hubs and move on. If you’re not in a position to do this yourself, then it shouldn’t cost too much to get someone else to do it for you. Should you have to be faced with having to do this on a new / nearly new car? IMHO no you shouldn’t, but it will put your mind at ease and you can get on with enjoying your car.
Good luck and all the best.