Log into where you did buy the mod, with the email address you used back then. Or check your inbox for the receipt maybe there's a link to re-download it there.
Do you think there will be a future update where you can add dummies into the backseats aswell? Like it will put 2 in automatically and you can add dummies into the backseats if you want?
maybe when beamng v1 comes out and everyone can run this game with 100000000000fps with 500 cars spawned on extreme graphics
if the devs of Beam find a way to optimize the game for more stuff to be added to cars without slowing down the game, then maybe. But as of now, no.
Have you ever seen the crashhard dummy? (not the 2.0) https://www.beamng.com/resources/the-crashhard-dummy.10550/
I didn't pay for the full version, but I think the mod is really coming along. I really like the demo version because at least you're able to see what the paid version is like. But, sadly, there are people who are as immature as modland users that are leaving bad reviews on the resource.