You guys can also go in together and share a DL-1. All you'll need to do is buy a separate power cable (either a cig plug from Radio Shack or a pair of wires to hardwire it into your electrical system), and the proprietary plug that goes into the back of the DL-1. If you want to keep your GPS antenna permanently installed you'll need to buy one of those too (it's a magnetic base, but you may want to secure the wiring with tye-wraps and not bother with removing and replacing it between sessions when you're sharing).

The basic DL-1 comes with a two-axis accelerometer and GPS inputs; this by itself is EXTREMELY powerful information, and a good basic setup. From there you an easily input RPM (same place you take it off for an aftermarket tach) and a brake input wire (run a wire from the ground side of the brake light switch to the DL-1 input so you can see when you touch the brakes.) Just by adding these two inputs you've nearly doubled its usefulness (and they're the easiest ones to do.) Best inputs after that are throttle position (if you have a TPS you can take it off there) and steering input (usually something like a rotary pot on the steering shaft or a linear pot on the tie rods).

Then, when you become totally enamored with the product (and you will), you can add the DASH-3 display, giving you shift lights and input warnings.

My preferred vendor for DL-1 products, and the guy through which I do my coaching/data acq work, is Jeremy Lucas of FastTech Limited. Plus he's an ITA competitor and an all-around good guy...

http://www.fasttechlimited.com/

GA