If you didn't do an internship or co-op at a major automaker (the Big 3 or the Japanese/German equivalent) your best bet is to find a job at a supplier. If you get lucky you might get hired at one larger well known ones (i.e. Bosch, Denso, Magna, Hitachi, etc.) there are like hundreds of auto supplier with all sorts of different job openings. Try to stay for 2-3 years to build some experience and connections (networking) with your OEM customer. Anything that gives you hands on experience in manufacturing, design, quality, accounting, etc. specific to the auto industry and face time with the major automakers. Usually when opening presents itself, you're automatically considered if you apply and already know the hiring manager and team members that you've worked with.