Pack light. consider earplugs. stop frequently and get out and walk to avoid the cramp you will get with no cruse control.
the car is actually very comfortable on long trips.
Enjoy the ride.
Pretty accurate assessment.
Drove from Park City Utah to Saint Paul Minnesota (~1300 miles) with the 2005 Elise sport pack I had just bought. Brought my buddy to check the car out (he has his own Elise), then hogged the wheel all the way home. He actually slept in the car sometimes.
Didn't need the earplugs with stock exhaust and the hardtop on. Listened to Spinal Tappets and several Car Talk car-song CDs. ( Haven't had the faceplate back in since.) Note; it seems that the slot between the driver door and seat is a good place to put CDs, but I cracked the jewel cases on a couple getting in an out.
Drove with the windows open for a couple of hours. Got tired of the noise/turbulence and closed the windows. Turning the AC on and off with the button was fine. (Around home, I just open the windows, have seldom used the AC).
Had enough room for all our stuff (two guys who packed light) and the soft top on its case. Found that a 17" MacBook Pro in an Incase EXACTLY fits behind the passenger seat. It is easy to put in, a bit fiddly to pull out.
Frequent stops are good. That said, I did drive 200 miles and hardly noticed it. Longest I drove in one day was 658 miles, and I felt no more beat up than a day at the office. The lack of cruise control was noticeable, but I found places to hold my leg to cruise. I didn't abuse the speed limits much, but that is easier out west where they are higher. The engine tachs right up in 6th at 75-80 (you'd think that with 6 gears they could give you one lazy cruiser gear), but the car does not seem to mind.
The windshield wiper needed a new blade, since the wiper had never been used. This may or may not be the case with your Austin car. I had good luck with a Michelin wiper from Wal-Mark in Park City. The washers were wildly out of alignment since they had never been used either. Bring a straight pin with you; you'd be surprised how difficult it is to find an adjustment tool for this when you are out on the road.
If I were alone driving my car from Austin to Harrisburg, I'd budget three days. More, if I could arrange to hang around with my Internet car buddies along the way.
Have fun, and don't parallel park anywhere.