Under the old 91+ day arrangement, we purchased our motorhome and when we appeared before the Franchise Tax folks, they liked the way that we'd kept our daily record while vacationing (100 days). We even had movie ticket stubs and restaurant receipts, as well as campground receipts. We flew to Europe from the airp[ort in PHX but stored our motorhome nearby while we took that trip.
The Tax folks had some hilarious stories of people who've tried to pull tricks....and the Tax Board folks aren't slow in recognizing the slight-of-hand. There's now no way of doing this in 91 days. It's a full year. The State of California is hungry for revenue, and so are many other states. They are working closely together to seal off any attempt to avoid taxes. Working with the CHP, they have even checked licenses in storage yards and, of course, are quick to pull over those people towing a car with a different (state) license. People who have a permanent CA address are, of course, the targets for this kind of "checkup". There's also a bad feeling among a growing number of residents when they think somebody is pulling a "fast one" to avoid taxes, so the Tax folks get quite a number of tips from neighbors who turn in such information.
If I'm sounding abrasive about this topic, it's because the heading "Sales tax avoidance" is a masterful way of using the very terminology that ligjhts the fuse with those neighbors who are likely to turn you in.