Hello, say I was converting a fwd car to rwd what steps would I have to take to make it road legal, presumably a vehicle inspection of some kind and would it be insured as a kit car or modified car?

Many thanks

If you are not modifying the monocoque bodyshell to any major extent save for the prop tunnel and boot floor then you should be OK
DVLA are more worried about tax so depends if engine size is bigger
There are a few Fiesta's that have changed to RWD and others converted to 4WD