Cindy and I never drive at night unless it's mandatory. In the past 7 months on the road, we've stayed in a Wal-Mart about once a week on average. There have been plenty of times we might stay in a different one for 3 or 4 nights in a row.
I'll admit that the first few times, I didnt get much sleep, but after awhile, you get used to the intermitten noise of a loud car passing by.
Our reasoning, if we've spent the enitre day riding bikes or enjoying a paddle until the sun goes down, and the next day we're going to be moving to a different spot to do the same, then why waste $30 - $40 just to be plugged in for the night?
Notice the 3rd camper in the picture has their Blue Tote out for their Grey Water!!!
Not one time have we been bothered and most of the time when we wake up in the A.M. there are 3 or 4 other campers in the lot with us. Just dont be dumb and put your jack stands down, or unroll your awning. We've seen people with their Satalites out, generators running and BBQ Grills out while in the lot!!
No worries, as long as you're not in a bad part of town, most know you're just there for the night. Heck, in Crystal River FL, they have dedicated parking spots for long term RV Praking in the local Wal-Mart. We stayed at a campground for a week, and ever time we passed, there would be more then 10 RV's in the Wal-Mart lot!!