I've done this on more than one occasion when I've made chases in the Midwest where I drive up the evening before and drive part way back after the chase. Prime example was my March 15, 2016 chase in western Illinois (one of my more successful marathon chases actually). I decided about 3pm the day prior that I was going to play that setup. I drove till about 1am and stopped at a rest area near mm 30 on I-55 in Illinois. Woke up around 10, was in the target area slightly after noon, and had a very good chase. Headed back, stopped at the I-44 rest area at mm 112ish in Missouri, woke up the next day and drove the rest of the way home. The Missouri rest area wasn't as bad as far as too much light goes, the Illinois was better lit than I would have liked. There wasn't a dark corner that I could find to sleep.
Now granted, I've had a CDL for a couple years now and drive semis for my regular job, so I get free showers at Love's truck stops. So sleeping in my vehicle and catching a shower isn't a big deal to me. But even back in 2016 before I got my CDL, showers are $12 at Love's, $11 at Pilot/Flying J, and $13 at TA/Petro. Some of the unaffiliated truck stops are less expensive, but they're also hit or miss as far as cleanliness goes. That said, I do tend to gravitate to truck stops and rest areas to sleep overnight, if only for the simple fact that I'm a trucker and like to have some type of restroom available for when I wake up. I've never been bothered at truck stops or rest areas, but it can also be difficult to find a dark corner. If I do that in the future, I may get some towels to cover up at least the windows facing any lights to help that.
Walmarts have gotten a lot more strict in recent years about people parking there overnight. If you get on google though, you can find out which Walmarts are friendly towards truckers and RVers. If they allow truck and/or RV parking, you should be good to go there. Just make sure they allow overnight parking, as some that don't ban them outright only allow semis and RVs to park just long enough to shop and get out. Personally, I avoid spending my money at those locations that don't allow overnight parking. But again, that's me being a trucker and thinking like a trucker.