Anyone have any ingenious ways of separating kids when their car seats are right next to each other?

90% of the time, they play, but sometimes my youngest is frustrated and repeatedly pinches the oldest. I'm currently using a dry erase board wedged between them, but my youngest is learning how to move it out of the way. In my dream world, there would be a way to install a limo window between them, keep it down most of the time, and roll it up when necessary... any ideas for something more realistic?

Due to our drop off situation and a tall husband, I'm not able to move one of the seats behind the driver's side.