Being a member of Powertrain (this applies to many other subteams as well), you can learn concepts taught in senior-level engineering courses and beyond, such as Solidworks and FEA/fluid simulations, fluid mechanics, heat transfer, design of mechanical systems, and statics/dynamics.
The number one quality of a new member is motivation and being eager to learn. We would much rather work with someone who does not know anything about cars but is willing to learn, than someone that thinks they know everything. FSAE is a lot more work than your average organization, so those that continue to stick with it and always looking for ways to improve are the ones that stand out.