When the coppers are looking the other way, haha. What I've found is that OBD can show as much as 255km/h or mph depending, as there is only one byte for the speed. The idea peterleinchen is to have the N900 speedo at exactly the same 'angle' as the real speedo.

At least I've changed Km/h to km/h (looks odd with the big K) and rpm to 1/min (which my vehicle has)

Still going to purchase the ELM327, but the application looks neat overall.