My 2 years old BMW is one of those heavily computerized cars and can easily be serviced at third party shops. There's a whole network of them that specialize in BMW service, maintenance, and modding. Not to mention that anyone interested can, ahem, 'acquire' BMW service software and start hacking away at their car. You need to expand your tool set to include an Ethernet to ODB2 adapter, but that won't stop even an amateur tinkerer like me. Teslas, on the other hand, don't even provide a working ODB2 port, and attempts to hook up to the car's internal network were met with legal threats.