Here is how the car panorama was shot and assembled :
I first shot 4 circular fisheye images (Coolpix 950) exposed for the outside. The camera is mounted on a tripod, the shots are 90° apart. I used the timed shutter release to be in the photos...
Without moving the tripod, I made another turn, this time exposed for inside of the car. Removed the tripod, then shot the lower part of the car, to patch the tripod.
I then assembled the four inside views using Panorama Tools and PTgui. Average distance 0.9 pixels, I'm quite happy of my tripod setup ! This original result can be seen here : http://www.philohome.com/panogallery/jpeg/car0.jpg. Note that everything outside is overexposed.
Keeping this 4 shots fixed, I then added control points between the nadir shot and the four others, then generated a panorama with only that image. I copied this layer over the four others, with a mask hiding everything. With a brush I then revealed that layer where it was necessary, i.e. over the tripod.
For each corresponding inside/outside shots, I then made another Ptools/PTgui round, the inside exposed shot beeing fixed to the values determined by the first assembly. I optimized the values of the outdoor exposed shots to match the indoor one, then generated a panorama. I then cut the windows and pasted them in the final panorama.
It took a while though...