I'm a newcomer to the Volvo scene but I'm in the market for an 850 turbo wagon (or possibly a V70 turbo depending on cost). I've searched all over the internet and can't find the info I need and I'm sure someone here has it all.

Some of my basic questions are:

Is there a site that lists the various options for the 850 trim levels over the years of production?

If there's no site, what are the differences between the GLT, T-5, and T-5R?

What years and trim levels had all-wheel-drive, if any? I've seen some listed that aren't Cross Country models but don't know if these are for real or typos.

I'd like the performance of an 850 T-5R, but don't know if I'd be better off with just a T-5 with aftermarket performance upgrades (like IPD). I'm not concerned with exclusivity, so would I be better off cost-wise "building my own" R model?

How different is the V70 from the 850? Was it just a restyle or is it a total redesign?

Also, how durable/reliable is the turbo? How much does altitude affect it's ability (sea level vs. 7000 ft)? I've heard that to prolong it's life you should let it cool down for about a minute before turning off the car, is that true? Are there other turbo "rules" to follow?

Finally, is there anything I should be looking out for while I shop? Things to make sure to get or avoid?

Thanks in advance for any help you can give me.