I have in my possesion some very strong magnets. These magnets are easily strong enough to fasten pressed steel plates to your car, or plastic ones if you use 2 pairs:
If you have smoothed bodywork and no number plate recess, or you change/remove your plates for shows then this is the ideal solution.
By mounting 2 of these magnets behind your bumper plastic ('no nails' glue to fasten them) you can simply stick your pressed plates to the bumper when you need them, then at shows, just pull the plates away from your bumper to reveal your super smooth bodywork.
Alternatively, if you used plastic plates, simply connect two to the rear of your bumper, and another two to the back of your number plate using strong glue, or you could even 'tap and dye' them if you are up to it then screw your plastic plates to them.
if on the other hand you have older bumpers, i.e a mk1 or mk2 golf with the steel behind them then you have no issue with mouting magnets behind the bumper, you just need two attaching to your number plate.
these are very strong magnets and well up to the job, check the picture of one magnet, still in it's packaging holding a full tin of paint!!
£5 a pair including delivery
if you need 2 pairs for plastic plates etc then i will do them for £9 inc delivery.
These really are very strong and very expensive to buy.
i have around 13 pairs avaliable for sale.
i can accept paypal, direct bank transfer or cheques
please email me at email@example.com to order, i may not check all the forums these are posted on at the same time and so one place to order seems fair
thanks for looking