I guess the least expensive and least "difficult" way to connect wold be to mount the iPAQ docking station in the car and use PPP over the serial link. This is directly supported by the iPAQ, but you may have to recompile the empeg kernel (i don't rememeber whether it has ppp) There are some very good and easy to undersatnd tutorials on how to set up this link. (you could also charge the iPAQ from the car.

The other alternative is to have a CF or PCMCIA-jacket on your iPAQ and an ethernet-card with a cable to the back of the iPAQ. This will give better bandwith, but usually a rather awkward iPAQ, as the card/canle will go out on top of the unit.

A PCMCIA-jacket with a wlan card is another good but expensive option.

A connection over IrDA is probably possible, but more awkward, and I do not know if the VNC protocoll is suitable for a high-packet-loss link?

Let us know your experiences. I have actually got an iPAQ and a jacket with WLAN plus an access point (And a car-power-to-clean 5V converter)...

Marius (Escort Cab + Mark II)