Dension is cheaper than Mobridge but not cheap.
I would go to there websites and ask questions .
They are pretty good about responding to emails.
Either one will require the CD option be programmed in if you don't already have it . I think one of them has an enabler but I am not sure
what it does.
I have seen the new Dension on Ebay for about 550 and there older model
without a2dp for around 425 US . Can't see how that would interfere with the MS-8 as that's and analog connection and both of these are hooked up through the Most Bus.