Hello,
I am going to do mine a little later in the summer, as I swear by Waxoyl on my XJ40. I have already painted some on into all the under arch areas, and into the air intake area where the pollen filter lives. When I come to do it, I'll take the following approach.
1 - Fill chassis legs at front from holes within the legs, let waxoyl dribble out
2 - Remove rear seat, waxoyl in any bunged areas
3 - Remove carpet, remove bungs and spray in waxoyl
4 - Kurust rear crossmembers, ensure free of rust and spray liberally
5 - Sod the doors, their rusty and need replacing on mine
.
6 - remove all inner arch liners and spray liberally in these areas
7 - Spray up past gearbox into transmission tunnel.
Will post a how to for anyone interested, once I have completed this. I've done my jag about 4 times now (once a year !!!)
Trick is to ensure car is clean, under arch areas are free of muck and that the car is dry.
James