European cars have no chassis and are of monocoque construction. Most of the lower rear panel of the cars are composite panels that go round the sides to the wheelarch. Its possible to put something in but you'd end up with something that resembles the worst type of install on Alans site - one stuck out in the air with no metal below it. It would also end up being something that would fail the annual MOT test unless you could remove it. All is not lost though. I'm at midlife crisis car age and a truck like yours would be seen as such a thing here in England.