Between the electronics, no, or at least incredibly unlikely, at least not to the human ear.....
Between the different speakers, Dynaudio and standard, yes, in all probability there is. How much, well that would depend on various things and only a (double) blind test would be much use determining that given the problems associated with audio testing and comparisons. Then there's preference to add to that; not everyone likes the same speakers for good reason. And then to top it all, you have the considerable amount of ambient noise in a car to add to the mix.
......Seems like there's some subjective audiophile ignorance showing its ugly head here. I'd bet you'd even recommend people to use $$$ external DACs too. 
For those that don't know, there's a lot of ignorance and myth in the audio world, considerable amounts of which is championed by "high end" A/V salesmen that make their biggest profits from selling ridiculously over priced cables to the unsuspecting public.....
A couple of things; first, the encoding algorithms used is just one factor. Another important one, more so in the past few decades is the mastering quality. A lot of music these days has little dynamic range due to sound engineers attempting to make everything so loud (do a google for "loudness wars").... but for .... audio, it's awful. Really, really, awful. Although this trend tends to be more restricted to popular music rather than classic.......
I'd disagree with the vinyl comments; poor dynamic range, pops and hisses, and all the other typical analogue issues. Valve amps are just over hyped, expensive, underpowered, room heaters that add distortion. They look pretty though......
WOW
That was like reading my posts on audio forums for the past 10 years!!
I thought there was only a few of us on the net, people like David Clark(home/pro audio), Richard Clark(autosound2000/pro audio), Mark Eldridge(MSE), Gary Biggs(JBL), Andy Wahmyer(JBL) were brave enough (to speakout against the
instilled truth) on the net.
I have working with Linn on my CV, I also have had 2 recording contracts, I've have had my music chart in the Scottish dance charts, I also have sound technology qualifications and I have played a gig in front of 20,000+ people at dance event.
i have heard and tinkered with almost all forms of music playback. I have heard music played back from a £20 sonly walkman right through to a £400,000 Linn system that would make grown men cry.
Have a little think about what you just said, and if you want to debate it properly it really needs it own thread but not in the mk6 section.
I seem to have missed some posts or skipped some so not sure what you agree or disagree with.
Im interested in what you actually did at Linn. I have worked for a highend English home audio company myself in the south
in the design and test section and it opened my eyes to the utter BS in the audio industry i was
let in on so many secrets and lies that are fed to people. Stuff is often used not for sonic grounds but because the marketing men want it!. In the electonics side of a system you can think of them as an electonic linear systems. So within the well documented human ears very low levels of been able to notice a difference like 1% THD for tones 3% for music, less ~30db channel seperation (defined by the size of the human head) , things like amplifiers can be looked on when used in there linear range as 'linear systems' so are defined by frequency responce, Gain, noise & distortion. Wiring in the audio frequency range can be defined by there LCR properties. etc etc. Theres no vodoo in audio just electonics + mechanics.
