Tesla was among the big winners, with its registrations up 93 percent. The EV maker's share of the market is 2.2 percent.
The UK is at risk of falling behind in the shift away from the combustion engine toward electric cars and could end up as a minor player in automaking.
For $1,200 annually, some Mercedes EV owners can cut acceleration times by about a second. More and more automakers are seeking a new source of revenue through such aftersales updates.