This whitepaper is a follow-up on car hacking that was an attempt to reduce this barrier to entry so more researchers could get involved.
You can download it from the following link: https://packetstormsecurity.com/files/download/142304/car_hacking_poories.pdf
Source: https://packetstormsecurity.com/files/142304/Car-Hacking-For-Poories-A.K.A.-Car-Hacking-Too-Electric-Boogaloo.html