Considering your lack of experience and limited access I think you got some very good results.
If you liked Baltimore do yourself a huge favor and attend a race at a track with excellent viewing from spectator areas and not a lot of fencing. You can get great un-obstructed shots at Lime Rock Park in CT, VIR in Alton VA, Watkins Glen in NY and Road Atlanta in GA. There are races coming up at Lime Rock and VIR that would be great opportunities. (all these are sports car events)
For fences you may have better luck standing back a bit but of course with general admission that's just going to put more people in front of you.
For panning shots you don't want the cars to end up looking like they are parked on the track so slow your shutter speed. Start around 1/320 and as you get acceptable results work down. Eventually you'll be able to get sharp results at 1/80 or even slower. If you don't have a monopod that would be a good investment.
Thanks! I used 1/200 as a shutter speed for all of the panning shots I posed (4) and I think I would've had no luck getting a sharp image with anything slower at such a close distance.
I've been meaning to invest in a monopod for a while now, should probably just bite the bullet on that.
Can you comment on my non-panning shots sharpness? I'm unsatisfied with how the cars look, and I think it's motion blur (1/1000 shutter speed) and not just poor focus, but I'm unsure.
EDIT: I did the Formula SAE program in college for a couple years and got down to VIR for one of my competitions. FANTASTIC course would love to go back!

