Since this has already been discussed in other threads, I'll give the short answer:

No room in the casing for a PCMCIA card, not enough demand to try to work one in, would make unit too expensive, etc.

However, the ethernet jack on the back of the unit works quite well in the car, and many people have come up with different solutions for plugging the ethernet cable into a wireless bridge running off of the car's 12v power. One of the empeg demo cars has an Apple Airport sitting on the parcel shelf.

For more information, please check the corresponding entry in the FAQ.

___________
Tony Fabris