dension 500s looks like a cheaper option
and it does more. they sell for around 550 on ebay
of course you have to enable the cdc and maybe kmp3.
Can't say if the 6fl route would work but its expensive
and convoluted.
I would imagine a CCC retrofit and the associated hardware would be north or 2k.
http://www.e90post.com/forums/showth...&highlight=ccc