Probably doesn't need to be said but remember a few things:
- No lights!
- No radio, fan, nothing electrical
- Be sure it's fully charged -- (2+ hours on a good charger)
- If it's in a position to do so, push start the car
- Bring a multimeter or a dash voltage gauge to watch the voltage plummet as you drive home.
Actually I'm curious how much juice it will take to go, what, 10 miles? Post the before and after voltage when you can

Last time I did this, it was in high school on a date driving home from the movies, I remember the lights getting *really* dim by the time I got home. It was a carbed car though, no ECU, so it was probably still running ok on 10 volts.
Will do on all accounts. Question, you're familiar with Miata layouts, where should I put the mulitmeter? I'm interested in seeing how fast it drops also.