After 4 years sitting in a garage my Golf is finally back on the road. It passed it's MOT yesterday

But.......... I've got problems with the zorst. It's a Mongoose full stainless system and it gets really really hot. Even with small bumpers the heat destroyed the back bumper, fried to a crisp above the tailpipes. I have now changed to big bumpers and to stop the same thing happening I got rid of the DTM tailpipes and re hung the exhaust a bit lower (it now bangs on the back axle when the car is fully loaded). I though all was well until today. Had the car out for a proper thrash and when I came back the bumper is fairly well melted. I'll post some pics in the gallery but does anyone have any ideas how to stop this ?
or why does my exhaust get soooooo hot ? The engine temp is normal and the oil sits about 94 - 100.