The first step to building the Roadtrip in a Box is the package.  You'll need a small box, some old map pages that you can tear up, some white glue and a foam paintbrush, some light brown stain and some spray on sealer.  I went to a craft store and bought a small brown box with a lid, but I think a shoe box would work.  Just make sure it has a lid.  You're going to cover the entire box with pieces of torn map.  Tear the map, making sure all of the edges are jagged and irregular, then brush them with white glue, stick them to the box, then brush over them again.  Overlap the torn pieces until the entire box is covered.  Then use the same process to cover the lid.  Let it dry.  Lightly brush over the entire surface with the stain to give it an aged look.  The final step is to seal the box with a spray sealer to prevent damage from moisture.  Package complete.  If you want to add a cool card, look for a chipboard tag at a scrapbook store.

The second step is to gather the items that you'll fill the box with.  Here's what goes inside:
$20 cash for souvenirs
a gas gift card ($25)
a food gift card ($20 to McDonalds or Taco Bell or something like that)
a roadtrippin' CD (something classic like Beetles or Springsteen)
a disposable camera
a map
The final item takes some research. You'll include an envelope with the "mission" of the roadtrip.  Search this site www.roadsideamerica.com for an oddball destination.  The point is to send your teen and his/her friends on a goofy mission to see something unusual, like the largest ball of twine in Cawker City, KS or the shoe tree in Middlegate, NV or, as I did, the double decker outhouse in Booger Hollow, AR!  Don't let them wander!  Don't let them go wherever they want.  You must choose a destination for them that is easily accessible by interstate and within 2-3 hours from home (so they can get there, visit, and get home in a day).  Print the information about the site and then print a page telling them what they are to do.  

"Grab your best friends, crank up the music and hit the road for a ROADTRIP!  Your mission is to locate (you can read a map, right?) and visit this destination.  Make it back by dark and the film processing is on me!"