Banpei's two door panda Trueno from Japan

[Ivan141]

About plastic welding: What I'd suggest is to melt a metal mesh backing into the back of the plastic panels you want to join, lets say about 4-5cm wide.
I have some of that stuff at home (roll of stainless mesh for kitchen strainers), then you need a big flat foot for a cheap ass soldering iron (have that as well, you're welcome to borrow it). Temporarily connect the 2 pieces in the correct position, apply mesh to back and melt the mesh in with the soldering iron.
That will make the join strong enough to hold up to abuse. Making it look good is a different skill. You can either try to weld in new plastic or you can just apply some bondo.
The trick to getting the correct texture is specialty work. Have seen people take silicone molds of the surface and press that against wet bondo / molten plastic.