Apple buys VW/Audi and rebrands (since the brands will be taking a big hit very soon), and consumers forget about dieselgate. Apple gets the infrastructure to build cars, as well as an eager dealership network. They throw money at some new designers to oversee the existing engineers and make the vehicles they want to make.
Book it, done deal.
Plus, Apple does software much better than VW. Nobody will ever find out if the A&W Golf TDI cheats on emissions tests.