I've progressed this a bit now following feedback
I've decided to drill a 10mm hole in the legshields behind the horn-casing to allow the power cable for the satnav to exit via a grommet
The cable exit will be obscured by a spare wheel holder to a certain degree

Here's a couple of pictures of the satnav mount I'm using


The power cable connects to a TomTom Rider quick release mount this this
You can get a security device to save the satnav getting pinched when you're away from your scoot paying for petrol etc..

I was originally planning on using a DC trickle feed off the regulator to power/charge the satnav internal battery. However for fear of damaging the satnav at low revs when voltage fluctuates up and down I've decided to use a small battery using the DC trickle feed to top up the battery whilst the battery provides a stable voltage to the satnav.
Cambridge Lambretta do a small battery tray which mounts to the left hand rear runner leg using existing holes

Here's the battery powering the satnav so you can see the size and fitting
The regulator is not connected in this picture and the fuse is on the negative leg the same as my GP200. I have since changed the fuse to the positive side of the battery.


My plan is to use a three way connector same as this to connect the regulator DC output to the battery +ve and the satnav
