Revell ITR

I'm pretty much finished with my Revell ITR but I can't seem to get the chassis connected to the body. The back part keeps on popping out. I cant get that metal exhaust tip on that tiny stub thingy on the exhuast. Any suggestions?

not sure about the chasis but use a little bit of glue for the exhjaust tip

All i did was drill out the holes where the screw pegs are and used the screws that came with the kit to attach the chassis to the body. and a nice lump of glue for the exhaust tip.

Does anyone have a muffler installed in their ITR kit? If you do, please show some pics. Thanx!