I've not had dealings with either of these in respect of my Trophy, but I've heard folk mention Birchdown Auto Services in Malpas, Cheshire, or there's BTT in Wigan who do Renaultsport work..
Worth noting that tuning guru's EFi Tuning are also more or less on the doorstep in Runcorn.
I personally get a well trusted local garage run by some now friends (been taking my cars there so long now that's just how it's become) to do my annual servicing and MOT stuff but for anything bigger (belts etc) my Renaultsport's go to Mick at Diamond Motors in Long Eaton, Nottingham for piece of mind - it's worth the journey for me.