Simple. Download each one that has some appeal.
Try it out and see if it works for you.
I have an 03 Focus and need a front end for the carputer.
Multi Media is my main focus... Dvd/Mp3 playback. I would love navigation as well. Any Help on best choices would be great!
Second that...however I think that ALL the front ends do what you describe...it comes down to interface/price/features.
If its for free its for me!
2 of the main free ones are Frodo Player, and Road Runner. Frodo is a nice fast and clean front ent, but is no longer supported for the most part. Road Runner can need a bit of configuring to get the way you want, but in the long run is worth it IMHO.