Indicators,fog lights,reversing lights,air bags,catalytic convertor, plus the millions it would cost ofr getting one crash tested I assume, but i`m probably wrong.
Yeah, you are
It depends how many you make, broadly speaking. If it's over a certain number you need full type approval, which does involve crash testing etc. I don't think there's any requirements for airbags though.
Smaller numbers and you can avoid the crash test, (factory-built Caterhams and Westfields for example) but there are lots of requirements regarding projections for pedestrian and passenger safety etc. Also emmissions, visibility, lighting, brake performance and balance, general construction, cockpit controls, basic handling tests, etc etc. Google "IVA Test" which is what you need to go through to get a single vehicle on the road.
I recently asked a friend who works at JLR what large manufacturers do about prototype vehicles, and whether they have to be tested, but he wasn't sure. Because I'm pretty sure that some of those wouldn't pass an IVA with all the wires hanging out and half the trim missing. Anyone know?