...but the junkyards in Riverview seem to be open 24 hours/day. After a certain time at night, all of the Grady's junk piles stop twinkling. I'm just curious how and why this got coded into Gradys. It's not a biggie.

But if anyone else ever plays inventors and finds this annoying -- get the junkyards from Riverview. Each of them has more than twice as many junkyards than Gradys and you can dig around until dawn if you want to.