I've never been to a drive-in, mostly because the trend had dried up by the time I was born. And it doesn't help the fact when you live in a Country where they can't operate year round.
But in 2021, during Covid, I attended a drive-in style concert with quite an amazing lineup, the two biggest being Serena Ryder and the Julian Taylor Band . It was awesome! What they had done was they set up a stage at one end of a parking lot and had everyone attending park in such a way where they could see the screen. Then you were given a radio frequency you would tune into and you were told to stay in your vehicle unless you needed to use a porta potties, and instead of clapping people were honking their horns. It was such a fun experience that I thought for sure this kind of thing would have caught on during our quarantine mandates.