A lucky few with cars old enough to have a standard DIN car stereo bracket simply popped out the FM radio and dropped in a DAB replacement.
But, essentially, radio listening in both car and home dropped off a cliff.
Edit: The Great FM Kill-Off was a double whammy as they simultaneously stopped broadcasting DAB using the MPEG2/L1 codex and switched to DAB+' HE-AAC.
This made sense, technologically - sound quality of low bitrate MPEG2 is not impressive - but the result was that most early adopters of DAB had to purchase new receivers yet again as early DAB sets did not support DAB+.
Further, leading up to the FM shutdown all the focus was on FM=>DAB, not DAB=>DAB+ - so during the switch, three of my four DAB radios went the way of the dodo bird without me even having realized it was going to happen. I wasn't very motivated to buy new receivers yet again...