Using good quality car parts

Why buying cheap parts can be a faults economy. We can all find stuff cheaper on the internet, and we all do it. But sometimes we get what we pay for. Even some garages source cheap motor parts for your servicing. We are well familiar with the signs along the road side, FULL SERVICE €79. This can be faults economy. I recently had a car in for diagnostics, the client had an engine light on his dash for his DPF, he told me that he just had a service on it, and when I enquired further, it was one of...