Rich sorry to hear your probs. Your car is same age as mine more or less, and I have connect Nav+ too.
Anyways, I took my 147 to Bishops earlier this year for a VDC/ABS issue. They had it for 6 weeks, and guess what, the car still has the fault. To top it off, the car was scratched on the lower front skirt, and I'm 100% positive it wasn't there before I left the car with them.
It maybe a distance for you, but I heard good things about Cleavland cars in Ash, and also Alan Gibson in Basingstoke...
I'm certainly not taking my car back to Bishops..