Does any carseat work in any vehicle? Or do you have to try them out and make sure they fit correctly?
We will be getting a new car before Baby, but we don't know what it'll be. Probably an SUV, so there will be space, but does anything else need to be taken in to consideration?

Re: Dumb question about carseats
BFP #1:10/31/10 DS born 6/22/11BFP #3:4/24/12 DD born 12/31/12
If you're looking at buying a used car, I would make sure and get one that has the LATCH anchor bars to use with the LATCH system car seats now have. They make installing and uninstalling car seats so much easier and it's safer. I think all newer vehicles have them now.
Unless you're buying a sports car or something small, I wouldn't worry too much about the car seat fitting. A lot of the car seat manuals even have directions on using a rolled up towel to get a better fit.
I just installed our new Britax car seat & the instructions said the LATCH system isn't safer, just another option.
I also used a pool noodle with our old car seat. Worked like a charm.
BFP #1:10/31/10 DS born 6/22/11BFP #3:4/24/12 DD born 12/31/12
I should have specified. I actually have two brothers who do car seat inspections (firefighter and EMT) and they say LATCH is safer because there's less room for user error. They have both told me that I would be amazed how many car seats are not installed properly.
We've used both ways to install our Evenflo Momentum and we can get it much tighter with the LATCH system. In our vehicle, using the lap belt is really difficult to install the car seat with though, it might fit better in a different vehicle.
Specifically speaking, no, because not every car seat is going to FIT in every car.
I suggest checking out this facebook group, it has carseat techs, and you can tell them what kind of car you are getting, about how big you expect baby to be when born, the price range you are working with, and they will tell name a couple different brands that should work well with your car.
Later on, you can even post a picture to the group, and ask them if they think it has been installed correctly.
https://www.facebook.com/groups/CarSeatsForTheLittles/