I started my project car the other day and left it there idling to charge the battery a little, after a little while the exhaust tunnel started smoking so I had a look and it was coming from under the handbrake.

It looks as though the tunnel was melting the wire insulation and the little scratch guard under the handbrake mechanism. It was folking hot!!!
The exhaust system it the standard tubing but it's got a huge mid box and a fairly free flowing back box. Interior is stripped too.

So basically I'm wondering, does the standard exhaust system heat the tunnel? Has this happened to anyone else? Or is my exhaust mounted too high up in the tunnel?

All the heat shields are there the whole way through. It was the first time starting iron a month but I still wasn't expecting that it would happen. But it was hot hot, like touching an operating temp radiator.

Are you sure there are no restrictions in the exhaust? No blocked cat for example? A restriction would heat up the exhaust gases

On this subject of exhaust tunnel, has anyone removed the second skin that's spot welded over top? Can you remove it?

I think I just have to get rid of the frankin beast of an exhaust and get a new one made, but no point until I charge it and get it on the dyno. The centre box takes up all of the tunnel and used to hit the ground before it was stripped, but I may be able to get away with it being lower now.