I have purchased a bluetooth Frogpad for use in my Land Rover Discovery Series 1 to which I have fitted a Megasquirt ECU (controlling both fuelling and ignition timing) and carPC (ex mp3car.com) with which to tune the Megasquirt ECU.
The sun visor serves to accomodate the 16:9 Lilliput touchscreen (impractical in the car) and I'm using an oldish Cirque Smart Cat serial touchpad (not very pleased with its performance). I recon I'll be fitting some trackball type pointing device in due course.
I'm using a chinese no-name usb bluetooth dongle. Getting the bluetooth link to work called for some trial and error guesswork but I managed to get it going.
Being really small (although the keys are "adult" size keys - a definite advantage in a car), the frogpad fits nicely next to the manual gear lever (on a pedestal I made) such that my wrist can rest and be steadied on the hand brake while my fingers then falls nicely to the keyboard without interfering with anything around it (including my leg)
The Megasquirt ECU tuning application (Megatune) calls for odd keystrokes (like ctrl-shft-uparrow, alt-L, ctrl-B etc) which I found the frogpad can deal with and with not too much hassle either. Other than that, I just have to type in the odd filename when logging ECU data.
We drive on the LH side of the road (in South Africa) which leaves my LH free and being a RHed person, I thought it would be quite a challenge to master the keyboard but it came easier than expected.
Although the frogpad documentation needs improvement IMHO, I was able to find my way.
Let's face it, mastering a new keyboard will take some practise and you have to put your mind (and fingers and time) to it. I found mastering this keyboard quite easy (but perhaps I am exceptionally gifted ) and although my typing speed is not fast (wrong hand and all), my accuracy is surprisingly high (having forced myself from the word go, not to look at the keyboard while typing, knowing that I would need my eyes on the road, or on the tuning gauges).
It is pricey (in this application) , but then, how much is your life (and that of your passengers) worth to you ?