A couple of weeks ago I tried to remove the 7 seat conversion from my car.
The belts had been fixed to the original mounting points, on the rear wheel arch.
When the spanner turned on the drivers side mounting point, a large metal plate with the captive seatbelt nut came out.
It has taken me 2 hours to weld the plate back in.
The problem is that the plate is under the rear wheelarch,with water and mud being thrown up to it so it will rust really quick.
If you have a R/R Classic, have a look under the rear wheelarches with a torch,or pull the small piece of carpet up inside the car.
You will be surprised how a thick metal plate is fixed to such a thin wheelarch.
Cheers,
SPIKEY.