When I was Alton I was chatting with Furie about this back corner of the park just sort of being about English history, myths and legends....A lot of potential rides themes, and it would sort of be speaking to your own audience.
So with that in mind, I reckon a Rita re theme should simply be to make it like a classic British car rally. It would only take a handful of simple changes...Replace the nose of the train with something like the front of this car:
http://2.bp.blogspot.com/_aJ4PnZD1A70/S ... nPoint.JPG
since the current trains look a bit too much like an American hot rod.
Repaint the trains in British racing green, also paint a number on the bonnet.
Do a bit of a renovation to the control booth, and do it in the architectural style of the buildings you see in Alton village. Replace the mesh railings around the station platform with white picket fences.
Finally, get rid of the tacky bits that don't fit in, like those tyres with 2d flames at the top of the poles.
I'd imagine all these things could be done quite cheaply, and you potentially wouldn't have to rename the ride either.