I've been using ATS for years now, and the manager remembers my surname (which in itself is difficult for most UK people) every time, even after not going there for over a year. I am very happy to recommend them for tyres and brakes. While I was there most recently, getting some new tyres fitted, I asked them to check my exhaust, as it sounded too loud to me. They came back and said I had to replace both silencers, the catalytic converter, as well as the 2 sensors at the cat. They quoted £680 all inclusive. Their diagnosis was 'blowing in 2 locations' Shocked, and on advice of other HK members, I went elsewhere for a second opinion and got a different diagnosis ('advanced rust around the silencers in 2 places, but no leaks at all'). They quoted me £260 to replace the 2 silencers. So - mixed feelings on ATS in Oxford.