I dunno what you have in mind exactly…but you could also have like a screen behind the car…with black and white footage of a road…or something else and make it deliberately in that look…
Could be a cool effect…
The only other way I could think of to do it without all the mounted camera stuff is to have the actors say their lines to each other, and edit the separate takes together. So they look like theyre talking to each other live. Do close ups on their faces so you cant tell its not a live conversation. Throw in some pauses for certain reactions. Edit those parts, then lay some music under it so it works. I guess you wont know whats best until you try it. Def do some tests if you can.
Thanks guys. Actually, those 2 suggestions already came into my mind. Pete’s suggestion I am going to definitely use, but since most of the scenes take place in the car…I have to find some alternative shots other than the close-up on the two faces only. The projection idea is one I considered too, it’s cool cause it will give the movie a Film noir feel too (I’m gonna shoot the movie in black & white, so that’s a plus). I’m just concerned it would look too fake.