to be fair, question is a little generic but I guess you mean in terms of ascertaining if it's a dog or not.
The engines are vauxhall built and very reliable. Suspension bushes can get a little creaky in cold weather. The interior can look a little tired if not maintained (flaky rubberised material).
150bhp, that can be remapped upto 195bhp with the official Hirsch upgrade or around 210bhp with other maptuners.
Three different trim levels, linear, vector and aero going up in that order.
I'm very pleased with my 2005 2.0t vector with 50k on after 18 months (same engine, different map basically). Very good value if buying second hand.
Every second thread here is a diesel related issue mainly and due to the particulate filters - I have deduced from myself that diesels are not good town cars anymore because of the need for these filters to self clean, which if not given the opportunity to do so, clog and affect performance. MPG on the petrol though for me is around 25 mpg (lots of city driving, occasional 30 mile run). Stick with the petrol as far as poss.
Dunno what else to say really. Good luck :thumbsup: