Starting out, looking for a used X5 - advice?

[plympton]

I haven't seen a sticky for someone starting out looking at an X5 as a vehicle, so excuse me if I've just missed it.

I'm looking at getting an X5 as a neat used vehicle for my needs - occasionally driving on adventures in Oregon that my current electric eGolf won't take (80 miles / charge on a good day). I used to own BMW motorcycles, and have a history of doing car work and tinkering - they sound like the bikes in that maintenance is costly, but you CAN do a lot of it yourself.

--> I can rent a Jeep (Free2Move) in my neighborhood if my car is in the shop super easily, have an eBike, and I work from home, so having it available 100% of time isn't a requirement, I just don't want to get stranded in the woods.

Are X5's in general reliable? They seem to start having major problems ~ 100k miles. Is this a fair assessment?

Would you get a xDrive 3.0 or 3.5? It looks like 3.0 is more bulletproof since it's a non-turbo engine.

Similar, a diesel or gas?

Should I get a used 2012 for about $15k + plan for things to go wrong, or a CPO/Newer 2015-ish for $25k, that has a warranty and not have to deal with stuff breaking. Should I hold out and find a used one with good complete records from a BMW dealer?

Any pointers on what usually goes wrong at about 100k miles? Am I just looking for trouble? Any checklists for what to look for in a used one?