Thank you.

What happened after I typed in that boolprop command was rather interesting.  Moving the driveway enabled the car to show up but no one got out and I still had the stupid driveway error message.  So I added another driveway in the original spot, and my character drives up in a different colored version of the same car and gets out.

The problem seems to be solved, but that was just too weird.  Needless to say, I learned my lesson.  No cars or driveways on vacation.  Walking's healthier anyway.   

I purchased a vacation lot for my romance sim in Takemizu Village (Green Thicket Manor), and because I wanted the option to WooHoo in a car, I decided to make a driveway and put in a vehicle.  I took my sim on a date, everything went fine.  Then I drove my sim into the marketplace, took a walking tour, the bus showed up took my guy and disappeared.  When the tour was finished I put my guy back in the car and returned to Green Thicket.  BUt when Green Thicket loads up, my sim and the car is missing, and this error message pops up "A vehicle is trying to return to this lot, but there is no driveway available.  You must first put down a driveway."  Both buy and build buttons are grayed out so I can't put down a driveway to replace the one I already put there.  When I look at the map of Takemizu Village, I see the Green Thicket Manor is there - with a wall right over the driveway.

Anyway, I'm trying various options, but I just want to know if anyone had come across this sitch before and if so, is there any solution besides just nuking the whole thing and starting afresh.