While average quality is likely improving over time, there are many fits and starts, including backwards slides. Tesla is constantly making changes, but they are not all improvements as far as the customer is concerned - many of them are to make the car cheaper or faster to build. Not to mention a machine can get out of whack, or a person tired or inattentive, especially when under special pressure like an end-of-quarter push. My car is VIN #112 and I am extremely happy with its condition (even after helping deliver a couple hundred new ones a few months ago). Some people still getting new cars have many complaints. A new car is statistically likely to be better than an old car, but you aren't going to buy a statistical sample so unfortunately that doesn't help you.
So, essentially, there are really no shortcuts. Any car new or old could be in good or bad shape, so you'll just have to check it out.
Note that I'm talking about reliability and quality. If it's a specific feature, like AWD or autopilot that you are looking for, then yeah there are generally VIN cutoffs you can find.