It's funny that you guys are referencing the "Melted Crayons" smell. No one else brought up the reason for the smell so I figured I could offer some enlightenment.

Old BMW's, old Mercedes, and old VW's smell like this. They use a wax based CIC (corrosion inhibiting compound) on some of the interior metal surfaces of the car.

As a former old BMW (81 528i) owner, and current owner of 3 Jettas, I can tell you the big 3 Euro manufacturers smell like this. It can be hit or miss as far as how long it takes for the smell to begin to be noticed, some may never notice it.

My wife's 03 1.8T Jetta GLS has 226,000 miles on it and smells like a Crayola factory pretty much all of the time. My 03 1.8T Jetta GLS has 162,000 on it and has a hint of crayon smell on hot days (mines black, hers is silver).

Jared