Seems as good enough a thread as any to garner opinions....
Got a 15 year old A3 that's going fairly strong - don't do nearly enough long distance in it though and I'm pretty sure the DPF is cooked so this December's MOT may be it's swansong. Last MOT passed with no advisories but took some effort and I suspect a tester looking the other way to get it through emissions.
Do like it though as the bodywork is fine and it's just a really solid family car that suits my needs and is cheap to run - £35 a year tax and sips diesel. I'm seriously considering putting money into it to keep it on the road if I can get away with a DPF clean or it's just a case of sensors needing replacing or whatever. A DPF replacement would pretty much be terminal though given the cost. Belt is due for changing as well but ploughing a good few quid in now could see it do another 100,000 miles.
Given the price of a 2nd hand car now sinking a good wedge of money into it now on those bigger repairs to get a few more years out of it might just make more financial sense than buying another second hand car which will likely have problems of it's own come into view pretty quickly given the end of the market I'd be shopping in.
Going down the leasing or PCP type stuff isn't something I'd consider.