Building supercars has always been a cottage industry that anyone can get involved in but nobody can dominate in the way Apple has certain classes of electronic product. There's a lot of choice, few buyers and it's not high margin compared with mass produced electronics at industry-leading markup even if engineers at the popular companies aren't more obsessed with beauty and speed than the bottom line.
What Rimac did was partner with big automotive OEMs for research joint ventures and sell a tiny number of cars and a relatively large amount of battery and drivetrain tech to other OEMs. Difficult to imagine anything less like Apple's business model than that.
Most of your cottage automotive manufactures are partners with a big brand. You can do many things on your own, but you want the large partner to supply engines (it is basically impossible for a small industry to build an emissions compliant engine from scratch - expect to spend over a billion $ in the R&D if you try - and you can only get that cheap if a lot of the engineering is done in places like India). You also buy your airbags from their supplier.
What Rimac did was partner with big automotive OEMs for research joint ventures and sell a tiny number of cars and a relatively large amount of battery and drivetrain tech to other OEMs. Difficult to imagine anything less like Apple's business model than that.