I don't know any in Middlesbrough myself, I do know that there's a few bodyshops on Longbeck Trading Estate in Marske. I got a wing that was dented and scratched fixed up for £60 and you couldn't even tell the difference afterwards. I think it was called 'Spraytech' and it was on the road behind the back of the petrol garage. There's also Marske Car Body Repairs and Marske Auto Tech on the same estate.