No mass car deployment, no success...
I've had DAB since the early days in my car, when I was crazy enough to go and purchase a Blaupunkt Woodstock. Since then I have moved to the States and used Sirius (where I could listen to Radio 1 in excellent quality), and now back to the UK where my new German car (6 months old and bloody expensive) can NOT have DAB retrofitted (thanks to this news I can now see why!!!).
We can all whine about the technology (not as good as FM, breaks up, etc.), but radio is a predominately in-car medium from a marketing/business perspective. The breakfast show used to traditionally make/break the success of a station, and whilst the ability to tune around has greatly changed this (particularly in relation to the afternoon drive show), the essence of listening while driving to work is still a key element of radio's success.
I live in South East London (someone has to!), and drive an hour to work every day. Because my journey is between Wrotham and Crystal Palace I lose the upper end of the audio spectrum due to a compromise that's had to be made so that people in South West and Central London can get a better signal. Couple that with the pirates who broadcast on every "spare" frequency (basically over Radio 1, 2, 3, 4, Classic, and between every local station) and it makes for a pretty undesirable experience thanks to the RDS handover attempts.
DAB, whilst not being perfect is operational, and in the thousands of miles I have driven around the UK (rural and urban) it's stood up pretty well. We have an urban spectrum shortage on the FM band, and unless we re-architect the entire band plan we're stuck with a need to upgrade to something more efficient.
So, car manufacturers - stop being cheapskates and make this technology standard. There is a trend for much cheaper DAB radios in the high street stores now so that no one can really complain about the price, but cars are where we are really missing out. AM and LW services will sooner or later switch to Digital Radio Mondiale but that's not common yet, so it's excusable that hasn't been widely adopted.
Ps. Germany phased out Analogue TV in some places a year or two ago. Doesn't seem to be really progressive in the radio world does it?