And yes, the driver may not be able to see what is happening inside the passenger area once the screen has been lifted, but keep in mind the party that rents the vehicle after you. Remember that any type of cleaning will become your financial responsibility if you leave the limousine in imperfect condition. So, you want to mark another item on your wish list, and you think maybe you should do it “in a limousine.” It should be fun, I suppose. While limousines have privacy screens and your driver won't see you once the screen is lifted, it's not a good idea to engage in lewd acts inside.
See it as a courtesy to the next user of the vehicle. Limousine drivers and drivers see a lot of strange things, things that even the partition can't hide. In general, on a reserved basis, getting a limousine service means hiring a chauffeur to take you aboard a spacious and elegant vehicle.