The problem with any 20-year-old luxury car is that the advanced luxury features are likely to start breaking down on you and those can be expensive to repair even if major items like engine and transmission are reliable. For that reason old luxury cars can be a poor choice, especially if you do not do your own repair work.

You absolutely need to have a good mechanic check out any used car before purchase.

My suggestion is be willing to travel. I live up closer to Albany, and we are fully in the rust belt, so the risk is higher up here of getting something with some hidden rust issues. I have traveled 500 miles one way to get the car I wanted, you just have to research, and check it out as best you can before you hit the road, then check it out thoroughly when you get there, and be willing to walk away.

I would also suggest narrowing down what type of vehicle you are looking for. If 4Runner was what you wanted, that would be a lot easier than a Lexus, the one downside is people know how good they are, so they fetch a high price even used and higher miles.

If you narrow down what you want, you can get more info from the people on this forum.

I second @chucktobias on being careful with luxury cars and their fancy Features. It adds more risk when buying a used car.

That being said, I was looking for a 4th gen 4runner, but ended up with a 08 GX470 because the price was about 5k better than a comparable 4Runner, and honestly it it better for what I needed. It had all the right stuff wrong with it, so the price was less. Paint was flaking, but I was able to touch it up until I could get a full paint job, and a little rust that I dealt with. It is more comfortable for longer trips, and it tows better than the 4Runner as well. I also had full records on the Lexus, as it had all the big stuff done at the dealership. You can sign up on the toyota website, and add a vehicle as your own, and see it's maintenance history, nice to know before buying.

I love the LS430. I love the look of it and I love full size sedans. I don’t own one but I kind of want to. It does have a Toyota/Lexus V8, so the starter is under the intake so if it ever goes out it’ll cost you either a fortune or a whole weekend to change it. If it’s already been changed, then you’re good for a long while. If it hasn’t then it’s only a matter of when, though being a Toyota product, the starter will last quite some time. I’ve heard some of them going 200k miles. Beyond that,  being an LS there are less shared parts and they didn’t make that many of them compared to say an ES, so parts availability may be limited and prices will be higher. That said, just as in the case of the starter, being a Toyota product, everything will last a really long time and you won’t have to change stuff often. It’s just a matter of how much of that really long time was spent with the previous owner(s). If you’re prepared to pay more for parts and maintenance, then you’ll be fine with it