+1 on the MO Meerschaum Eaton, though I don't tend to smoke inside the car. My daily commute is 40 min each way, but I don't find enticing rolling down the window in 92ºF temperatures, with all the noise and pollution of the PR-52 Highway traffic jam.
I just fill up whatever pipe I'm in the mood to smoke, smoke as much or as little as I want, then put the pipe down to rest when I've had enough. When I'm ready to smoke again, I just relight and go.
I bought a MM Shortstop and can verify that fully packed it is a 10 minute smoke. We have organized breaks at work and I like to hang out with a lot of the cigarette smokers and this is perfect for doing so.