Hello, big thanks for the "Follow me" mode !

A few random suggestions, if they happen to inspire you :

- Automatic adjusting of the scale, based on vehicle speed and/or type of road and/or distance to next turn/exit/merge.
In city, being able to see close street-crossing details is helpful, whereas on high speed highways, being able to see further down the road is useful.
After-market satnavs (like Tomtom, Garmin) tend to do something along these line, which is useful given that there's no way to quickly change scaling using some on-steering-wheel command (unlike in-car built-in satnav, which could use the on-steering-wheel mouse-wheel-like selector).

- Signaling when speed exceeds more than 5mh/h above speed limits (e.g.: by have a solid-dark- or pulsating- red background behind the speed indicator)

- As discussed by others some time ago : announcing speed limitation change down the path (either along the routing, or further down the same street/highway in "follow me" mode)
Gamin have a "In 250m, speed limitation changes to 100km/h" warning pop-up top bar (basically the same type of display as routing instructions)

- mini cosmetic change : Street sign colour.
Currently, the colour of street sign is hardcoded (they show blue on the highway, like in France). But that actually varies by country (Switzerland and Germany have it swapped and use green on highway instead).
Do you think it would be possible to extract this information from somewhere ?
(I can send you an XML ripped from my satnav if it's of any help. But obviously it couldn't be used directly due to copyrights).

- random ideas to make instructions clearer :
-on Navteq in-car, the display goes into split screen. Next to the regular perspective few, there is a top down view zoomed on the exit, round-about, etc.
- on Tomtom satnavs, the screen is replaced by a cartoon showing the signs and underneath a plan of the path that needs to be taken
(Garmin Drive Assist uses a combo of stored photos and live-feed from the dash-cam to show the exact actual exit)
The latter isn't currently possible, but if the former two inspire you.

- heavy visual change : fish-eye perspective
Currently, perspective is done by tilting the rendering plane. ie.: the tiles are rendered along a grid reminiscent of 80s design. Would it be possible to instead render them on a distorted grid (think of the Blue Sphere bonus levels in Sonic 16 bits games). That would increase the render distance on distant parts, without decreasing the size of closer elements.
That might be a bit more difficult to achieve.

- easter egg : if stellarium is installed, have it render the actual real-time sky-sphere :-D
ok, just joking for that one.

- hardware note : I've bought and tested an OBD bluetooth dongle with obdfish.
Fun fact, the speed reported on the OBD bus is the true speed (very close to what the GPS detects) and not the "+5km/h faster to avoid getting sued in case of underestimating"
But it seems usable for out-of-satellite sight.