It’s becoming a forgotten art, converting one model into another prototype.  When I was a teenager, Triang GWR Clerestory coaches could be made into almost anything, with a new roof and a bit of cutting and sticking.

But this article suggests the art is far from dead – at least with old BMW cars!

Cinders and ashes! Police stop Thomas the Tank Engine on M1 motorway

A driver has received three points on his licence and a £100 fine after being stopped driving an unconvincing  Thomas the Tank Engine replica down the M1.
David Scott was pulled over on his way to Dover for ‘Scumrun’, an annual charity rally with a mystery location only unveiled at the start of the event. Participants tend to drive heavily modified cars, though in this instance the ‘tweaks’ made to the his BMW 5 Series were deemed to be illegal and unsafe.

More pictures here showing exactly how it was done.  But it’s not that convincing really….