I'm considering buying a 07 Lexus 350 RWD Automatic with 171,000 miles. Are there any common problems on a older model Lexus with this high mileage?

 

I got an 06 with 150k. Check the service history, Mines been well taken care of so that's why I like it. Do you have the touch screen? Those go out it's done that on mine. Also the dashboard and plastic molding melts if it's not been updated. That age the alternator could be replaced if og. See if it's had transmission fluid drain and fills, that helps extend the life and I did it on mine which helped smooth the shifting like butter.
What else..... standard maintenance, belts, plugs, pulleys, fluids, water pump, radiator cap, rad hoses, brakes, etc. I plan on keeping mine for another year or two before I truly consider selling it. The only thing I've seen for older models is leaking oil from that gasket issue that had a recall done for it or a tsb if I'm not mistaken, or it could burn oil.

 

My 07 is350 had the rear calipers seized around 80k miles and alternator died at 100k miles and one rear wheel bearing was making noise around the same time, but after got those replaced and trouble free until now at 142k miles and got total last month by accidently drive into the high water last month

 

Basically the exact same scenario/same parts for me. I'm now at 144k miles.

If your panels and dash have been replaced already and the car has a good, comprehensive service history, then I would say go for it!

 

That age and miles may get the rear axle boots too. Not a hard job if you're DIY and the vehicle is rust free.
That said, 175 to 200 and likely the dampers are need of replacing too.

See if you can get any history of transmission flush too.

 

I have a Lexus for sale, check my post