XC90 Buying Guide?

[Jazzop]

My mother is looking for a replacement for her Accord, which has an imminently expensive transmission failure on the horizon (Google "Accord V6 automatic transmission bad" for more info). She is firmly fixated on a high-ride-height, small/medium SUV offerings from Subaru/Honda/Toyota. I tried to sell her on a wagon, which would be a perfect fit for her typical automotive use-cases; but like most American idiots who previously owned a GM or Ford wagon between 1972-1988, she has severe wagophobia.

There seems to be a glut of XC90s on the lightly used market for a total steal. And my mom did like the design and appearance of the car when I showed images & flash animation to her. Since I know nothing about this vehicle, I'm hoping the enthusiasts can give me tips on choosing one.

Note 1: I am primarily considering the R Design or the V8.
Note 2: I am intentionally not mentioning specifics about the way my mom uses her car, as I'm not yet ready for opinions on how the car might "suit her". I just want to focus now on whether it meets my engineering, build quality, performance, and maintenance standards, as I am the one responsible for this stuff.

I humbly solicit:
1. Warnings on year ranges/models/trim levels/drivetrains/packages to avoid.
2. Options that are so indispensable that I should only look at cars that have them (assuming I can't retrofit them myself).
3. Failure modes that are common, expensive, and/or not DIY-able. Especially those I can use during price negotiation.
4. Common aftermarket upgrades that I can expect to perform when something needs repair/replacement. I use this info when looking at a car in order to fine-tune my decision on what degree of "needs work" is worth the hassle in exchange for a lower purchase price. Knowing I have to replace the shocks with expensive stock units is more likely to be a dealbreaker than knowing I can replace the bad shocks with lifetime Koni units and get better performance to boot. A Homer Simpson "crisitunity", if you will.
5. Any links to factory model brochures, spec sheets, and/or accessory catalogs throughout the XC90's production run.

Thanks in advance!

[matthew1]

From the Volvo Buyer's Guide category in the Volvo Repair Database:

You just bought a used XC90. Now what?
XC90 Buyer’s Guide
XC90 buy: T6 or V8?

Not directly answering your questions, but there's some good XC90 information in those. Avoid T6 XC90s.

[Jazzop]

Well, the search is off. She went and bought a Honda CRV essentially on a whim. Thanks anyway.