What should I inspect before buying a used Lexus?

I’m getting pretty frustrated with my current car, so I’m seriously considering a used Lexus, but I’m nervous about buying someone else’s expensive problem. My budget is around $18,000 and I’m looking at older ES 350 and RX 350 models, probably 2012–2016, mainly for commuting and occasional road trips in the Midwest.

So I was thinking reliability should make this fairly safe, but every listing seems to have something missing, like incomplete service records, multiple owners, or vague answers about accidents. My logic was to get a pre-purchase inspection, but I’m not sure what a normal mechanic would actually check on a Lexus or whether I need a specialist. I’m especially worried about transmission issues, oil leaks, suspension wear, rust underneath, and expensive electronics that might not show problems during a short test drive.

What should I inspect or ask about before buying? Are there specific Lexus years, engines, or mileage points that deserve extra caution? Also, is a clean Carfax and regular maintenance history usually enough, or are there common problems that sellers and reports tend to miss? I don’t want to rush into another car and regret it a month later...