depending on the state (i dunno the laws where you are), you *should* be able to get a temp 3-day registration online and print it out. then hop a bus or whatever for $50 with some food and your riding gear. call your ins co ahead and get the policy set-up (to save time later), then call back once ya have title in-hand and have them start the policy and e-mail (or maybe even fax, if you're really worried bout gettin pulled-over) your proof of ins paper to the closest Kinko's or whatever... enjoy the bonding ride home on your new S3!
...shipping is slow. it costs a fortune. they damage stuff. you'll have to buy it sight-unseen, and if there's new damage, the shipping co and seller will blame each-other.
i've bought 3 bikes and rode em home from only 140mi to 820mi...SO MUCH FUN
...i'd only ship if the bike was already in my possession and i couldn't replace it if i moved overseas.
whatever ya decide...yay new S3!