Hi guys thanks for all the info, great responses sorry for late reply, I was fixing/upgrading my laptop and couldn't manage to log in to this forum from my phone to reply for some reason! That's a great example, lots of ideas there which will really help me. I'd be looking to do some of the upgrades but a lot more modest (maybe I'm getting old but prefer a car that looks boring but goes fast!). I'm looking for exactly the same thing, a standard car that's been well-kept, and doing upgardes myself.
The viewing went really badly. It was on a farm and the car had obviously been sitting there for ages. They hardly knew anything about the car at all, and didn't even seem bothered if they sold it or not (and didn't seem to appreciate that I'd come a very long way to view the car with the intention of putting a deposit down, seemed like they were hoping to sell to somebody who knew nothing about cars).
[P.s. was trying to attach pics of the rusty exhaust but not quite sure how to do it on here...]
The condition was nothing like what was described to me on the phone. So I didn't put a deposit down. Did a test drive and the clutch/gearbox felt extremely stiff, also the brake pedal felt loose and the brakes seemed not very effective at all. Other than that it did seem to drive quite smoothly, so it gave me a rough idea of what these cars are like. Looking on the bright side it made me realise I definitely do want one of these cars, it just ticks all the boxes for me! But getting back in the Skoda made me also realise I currently have a nice car in very good condition, so need to look very carefully before finding a replacement.
I had a quick look under the car, and took some photos. I understand that exhaust rust is a problem on Foresters, however it looked really quite bad to me. The photos are not very good but I've posted a couple here. I find it difficult to believe that this is a normal/acceptable amount of rust?? Annoyingly I saw another example which was probably much better but has now sold before I got the chance to test drive it. But I also saw a 2004 model come up this week which looks very good, so I'm going to make enquiries there. Anyway I'm not really in a rush, as I have a decent car, so there's no pressing need to swap immediately, and my Skoda is having it's service on Thursday anyway. So I will just wait around and see if I can find a perfect example (also possibly looking at Volvo S60R, but prefer the Subaru because of the bigger space and more off-road potential).
Going back to the technical details, regarding the secondary air injector, for some reason I can't find the thread which mentions this problem (I was going to post the link). My understanding was that it wasn't just the error message popping up, but if there is actually a problem with the injector then it can be really expensive to fix. I may be wrong though. Also does anybody know if this is definitely only a problem with the 2006 models and went away with the 2007? To be honest I don't really see a problem with going for an older model (2004/5), if it's been well serviced. Actually I think I prefer the older body style (a bit more square) to the facelift which I think was in 2006(?). Also I've read somewhere that the tax band after 2005 goes up to over £400/year rather than £275 or something like that, so that's something to consider (can't remember the exact figures). So it seems to make sense to go for a slightly older one in a lot of ways, then more cash left over for mods too. ;)