You do get to transfer a certain amount of money. I think it's based on your lvl in fm3. I was lvl 37 and it gave me 48k credits. My friend was lvl 45 on fm3 and he got to transfer 60k credits. You get to transfer a few cars as well.

Here's a link that explains it
http://forzamotorsport.net/en-us/underthehood2/