I'd suggest checking out the SD Craigslist for rideshares - they probably have a category specific to it. Post your desires(ride share. not uh, you know), and see if someone picks it up. Or see if you can get a ride to Palm Springs, which is (kind of) close to JT. From there you might be able to hook up a ride, or use the bus to get to JT and hitch the final leg.
I will be in JT by then, and might be available to come get you in Palm Springs(but not San Diego). It would depend on my cash flow at the time though, which is extremely sporadic. When I have it, I can do things, but when I don't, obviously I can't. But as time gets closer, if this seems like "yer last hope," then feel free to send me a note(Obviously not at the last minute).