Better alternatives for next time.
To reinforce what has already been said, and as one who spends a lot of nights sleeping in my van, the last place I would stop is a rest area. As mentioned the 24 hour truck stops and other businesses are generally safe, with permission. Permission is most important as vehicles which look like they are just parked are often towed.
As Michael said, FL introduced security at rest areas after a whole family was murdered, years ago. In MS there are rest areas with overnight security. You see the signs on your approach. I still always speak to the security officer, and ask where the best place is to park. Then they know I am there, and keep an eye on the vehicle overnight.
Like eveything else, just because you got away with it this time, and I am ever so glad you did, don't assume that it is always safe. Try to make better choices next trip.
Lifey