This is just as you've stated, a proactive move to get what business is out there, cause those storage areas are full and that production line is far too expensive to stop.
Plus, those newly introduced road tax charges on new vehicles hasn't help their trade, and the governments pending ruling on city emission charges on vehicles.
There was a good article in the FT (March 24, 2017 5:56 am by Jonathan Eley
Are the wheels about to fall off car finance?) dig it out worth a read if your interested.