Bent rim - again

[Pominoz]

My Boxster has 18inch turbo twists that look great, even better with the wife in the picture



Anyway, one of the front wheels was quite badly buckled when I bought the car, but not picked up by the PPI unfortunately. Luckily it was straightened by a local wheel repairer with no problems since. I'm not sure if the roads in Australia are particularly crap, but now one of the rear wheels has a small buckle. Not as bad as the first, so this is the second trip I've made to the repairer. I can't even really remember where this would have happened. It can't have been an obvious pot hole because I'm pretty wary of the road surface in general and I think I would have noticed.

I was wondering if this is something that is quite common, or perhaps more common in 18 inch wheels. Has anyone else had much trouble with their Porche alloys?