Are the 18 inch wheels susceptible to buckling?

[RRTuscan]

I know this problem has been reported before, but lets see who else has had this problem. Ive got a W reg Red Rose Tuscan with the 18" wheels. It has just been in to dealer due to vibrations through steering wheel and general handling problems amongst many other things. 3 wheels are buckled or have flat spots. Hmmm, me thinks that there is a design fault with either wheels or wheel/tyre combination. Im not the only one to have this problem. Factory will not cough up replacement wheels as it is ''wear and tear'' The car is only driven at weekends and I do anything and everything to avoid pot holes. Im sure an independent test will show that the wheels are not up to the job. Lets hear from anyone else please. RR