After I showed this to a few people, I found out that there is a book called "Manifold Destiny" on this very subject. I have not read it yet, but I'm told that there are quite a few recipe's with locations and times (miles).
Step 1: Gather Some Ingredients
+Baked Chicken and Herbs (chicken breast, flour, your choice of herbs - I used mostly basil)
+Italian Chicken (chicken breast marinated in zesty Italian salad dressing cooked with pepper and onion)
+Red and Green Peppers and mushroom Noodles (used noodles from a ramen package, added a little EVOO, and cooked in vegetable stock)
+Baked Potato Pieces (salted with a little cooking oil)
+Baked Apples (sliced in half with a pat of butter and scoop of brown sugar)
Step 2: Prepare
The chicken breasts will be cooked in rectangular like packets to expose as much surface as possible. We want a cup like shape for the noodles/veggies.
Step 3: Sealing
The noodles require a little extra care. As we're adding fluid (veggie stock), we need to make out 'cup' with a sealable opening. However you feel is best is the way to go here ;)
On the note of toxic gasses (I'm asked this all the time)
If your car is emitting gasses (say exhaust or coolant steam) from under the hood, you have a problem and you should probably have that looked at. A maintained car does not do this which is why I'm not concerned with doing this.
Step 4: Placement
Potato and Chicken will require the most heat so they should be placed on or near the exhaust manifold. Apples should be placed near something hot (I put it on the top radiator hose). The noodles can be placed on top of the valve cover (if possible) as they can take lower heat for longer times and still cook properly.
Step 5: Cook Time
After the 100 miles, the chicken was well browned -- I think 60 miles would have done the trick.
At this time, the noodles were done, and were moved to a slightly cooler area. The potato package was still raw as I had placed it in an area too cool to cook properly.
Step 6: Other Suggestions
On my next long trip, I'd live to make a rack to support a pork roast or even a rack of ribs to cook slowly.
This type of cooking requires some practice and experimentation. But what's better than pulling up to a gas station and pulling out some chicken wings from under the hood while you fuel up?
Drinks! The striker plate (the part that holds the door closed) on most cars is a great glass bottle opener should you find yourself in the middle of nowhere with a coke and no bottle opener ;) Just look inside the door frame for something that resembles a bottle opener.
BTW, this is a '97 Mazda 626 -- equipped with bottle opener and oscillating vents (for some goofy reason) :P