There was a "drive-in" which used inflatable screens in Maryland a few years back, they tried 2-3 different venues and eventually gave up.
There was one in Hershey, PA, that is now doing free movies and making their money from concessions and sponsorships, playing movies that are over one year old. Low overhead, but also low revenue.
The one at the Orange County Fairgrounds near LA went belly up after just one season.
None of the above ventures even remotely compares to a real drive-in with a permanently built screen and parking area, which probably has something to do with they they've all failed. Cheap imitations will get you so far.
Rick