Never too Early - part 2

So last November I started "potty training" Jane. I hoped to make it easier to transition out of diapers as well as reduce the daily diaper count. Jane turns 18 months on the 25th and I've been trying to kick it up a notch to see if she can be fully potty trained before the next baby comes out. I got my inspiration from this woman...
My Great-Aunt Helen. Pictured with her is me, her son John, Jane, and John's daughter Josie. (Wow, that's a lot of J's.) Great-Aunt Helen is an amazing woman and managed to never have more than 1 child in diapers at a time. I'm not sure what methods she used or if she even remembers, but I've been inspired nonetheless.

I'm just not quite sure how to transition Jane out of diapers. Jane is fully "poo-poo" trained (don't worry, no pictures of that) and is really good about telling me when she needs to go. Pee-pee on the other hand, not so much. So I decided to try an idea I got from BabyCenter.com. Essentially you just have your kid run around with a naked bottom (they said for 3 days) and encourage the usage of the potty whenever they need to go. This is for toddlers going from zero to trained. The author of this idea warns about accidents and preparing yourself for the occasional clean-up. But from day one of giving it a try, Jane didn't have an accident - not once! She managed to tell us or go by herself when she needed to use the potty. The only problem is, once the diaper goes back on for nap time or bed time, she's not shy about using it for its designed purpose. We still go through fewer diapers, but what's the next step? Do I just brace myself and allow her to go diaperless? The other fear I have is whenever we go out. Will she be able to hold it if we're in the car and I can't pull over? I rationalize that we have until next February to really get her 100% potty trained, but she's so close! Even last night when we were at a restaurant, she signed "bathroom" and as I helped her balance on the grown-up toilet, she pushed my hands away and sat there all by herself!

As an aside... I captured these pictures of Jane reading a book while she was on the potty. It's just so hilarious! :)