Cracker Barrel and Pilot/Flying J questions

Haven't done Cracker Barrel so no experience there, but we have on occasion overnighted at Walmart, Flying J/Pilots, plus casinos & rest stops to add a couple of more. For us, it's only done to make time as we arrive late into the night and park to get a few hours of shut-eye before hitting the road bright and early. Always drop a few dollars getting gas, meals, and time permitting, even stock up for the trip ahead. We rarely have had to ask the manager as there is always quite a few RVers, truckers, and those in personal vehicles already present by the time we arrive, all trying to catch a few winks. This in no way is camping, or should resemble such, we just roll in and find a level spot, no unhitching, just grab what we need out of the truck and head into our rig. Finding a spot along the edges of the parking lot allows for safe slide extension over the cement curbs.