Recently took a National Express Trip Exeter - London Victoria - Norwich and back. The outbound journey was comfortable, the drivers informative and just an hours delay that was clearly due to traffic conditions in London. The Norwich - London Victoria return leg was on time and a comfortable and enjoyable journey. I would have given 5 stars but the London Victoria to Exeter return leg (NX504 - PP19) let the otherwise very good service down. The air quality was appalling, the fans were switched to maximum and made lots of noise and it was obvious that the air was being recycled. It was very stuffy, clammy and unhealthy.