I think that's overstating it, there's a lot of engineering in the UK. It just has a very low media profile, because it either has a foreign name on the product (Nissan!) or doesn't sell to consumers.

A surprisingly large amount of it is in really unglamorous buildings in industrial estates outside cities other than London. Since the media have largely stopped bothering to leave the M25, it's invisible.

(I have a pet theory based on the car industry that the really toxic thing is British labour relations; there are successful small British companies, and successful large plants with foreign owners, but all the British-managed mass-employment industries collapsed in strikes and/or were looted by the directors like MG Rover.)