Like Wooly I currently use a HP iPAQ with a Sysonchip CF GPS card (which I can throughly recommend) and run TomTom 5 and it is very good (although TT5 needs a signal to be able to plan your route). From the brief look at the Civic sat-nav I got from my test drive I would say the actual road representation is better on some of the 3rd party sat nav units eg its more than just one single line. Before I went for the EX I was also looking to get a separate unit in case I went down the ES route for the glass roof. Although not the very latest the Navman ICN520 is going for £190 from Halfords. There are quite a few units reviewed on
www.pocketgpsworld.com.