The last part puzzles me. Since you don't know the difference between Foley and PFX how on earth can you make the last statement. You have no idea what mics they used. A high priced mic means nothing in the wrong hands and wireless mics are used ALL the TIME in high budget films.
Well, I don't think I made a statement as to which mic was used in a Foley situation... sorry you lost me there. I was simply referring to the fact I would want my money to go towards capturing dialog properly on set and then Foley as well. I think logically... this of course wouldn't imply that Foley is recorded on set at the same time as dialog. I'm simply speculating on the fact that my budget won't accommodate a professional to do each and every job necessary for optimal sound.
I don't have experience making film at all; only doing simple video work. As this is my first time, just trying to get the facts I need before hand. A lot of this will help me in doing a couple 5-10 minute short films before I actually attempt any kind of feature. It's interesting you mention the car wouldn't be moving during a scene with dialog. I haven't found this to be the case in many behind the scenes segments / featurettes, and other times I've witnessed this being done on a set. Is not a lav mic or ADR common in situations where a vehicle is moving? It's still incredibly obvious these days if a moving car shot was done in a studio / blue screened, and I don't see it done that way every time. In film... man, I couldn't even begin to count how many times dialog is recorded in moving vehicles. Even take the new Total Recall as a recent example, plenty of dialog shot while the car was moving and not stationary in front of a blue screen.
I get what your saying in regards to ADR, but the more I read about it, the more it surprises me how common it seems to be in film. A couple months a go I watched the movie INK, and sent the Director an email asking what mic / sound setup they used. Anytime I see a low budget indie movie like this that has great audio, I like to find out how they did their sound, since that's usually the weakest link for any small production. Coincidentally I got a response email yesterday as I was in the midst of reading up on sound recording. Turns out all the dialog in the film was actually ADR. I see the value though of treating it like a measure of last resort, and getting the best possible audio on set, this makes perfect sense to me. Although, it seems like a pretty necessary option in situations that can benefit from it.