24 bit and 16 bit? and other question

Hi as yous all know I dont know too much about this stuff, is 16 bit or 24 bit going to make any noticeable difference FM radio, I think all my source stuff is 24 bit in studio, well the cards at least. But I was thinking then if your mp3s are only 320 k and your output is 24 bit are you going to be getting more emptyness if that makes sense? Does RDS still work at 16 bit?

Also stereo enhancers – why are these important and do they make a big improvement? I googled about them and theres mixed opinions but everyone seems to be talking about the new one here.

Thanks : )