Strange question, as I have been looking for the same. Which car are you looking at Kincath? I couldn't find anywhere near Norwich, the best is McGrath in Kimpton, Herts which is about 70 miles away. They will do a PPI but only on their premises. Christian Lewis are the same, you need to get the car there.
If you want a guy to go and see the car, then I was recommended Mark Wibberley at
http://www.morethanpolish.com. You can get him on 01780 749449. However, I'm not sure whether they will be able to do the same OBD check.