The use of DAB in cars has got to be a minute fraction of the radio market. Even the car manufacturers avoid it - there's no market for it. FM is too deeply entrenched and is a much cheaper technology without all the drawbacks of DAB: poor battery life on portables, poor reception, low quality signals through squeezing too many channels into the bandwidth, appalling time delay.There's an enormous stockpile of FM, Short Wave and Medium Wave radios out there, with many people having more than one radio in the house. The cost of replacing all these, when there's a perfectly good system that doesn't require an expensive purchase, will always put people off.
DAB is a seriously flawed technology that is already badly showing its age, and other countries in Europe and elsewhere have decided to use alternative systems. Whatever the next technology is that the government decides to inflict on us, needs to be rolled out and let's just forget DAB - it's had its day and few are really interested.
I have a Roberts DAB/FM radio in the kitchen: DAB is never used. I've tried it and it just doesn't work for me. I like my FM radio in the kitchen, even with all the background hiss. I can still listen to a good broadcast through the Naim tuner in the lounge, and I'm pleased to know that it's given me ten years service and is highly likely to carry on until that fateful day when the FM signal is finally switched off. I've always been put off any kind of upgrade as the Naim tuner cost me £600. A replacement Naim tuner with DAB is around £2500 for something of similar quality. I'm not tempted!
Nick