I ran into a problem with my ODY Grounding System, it was quite seriouse one, but I do not want to post it until I recieve a report from the dealer on the basic cause of what had happened. Anyway, there are at least 4 grounding points right under the dashboard which you can connect your Scanner G wire with. Other questions, I do not have an answer for. However, I would suggest you consult the dealer before you proceede with installations, see if this will affect your waranty or not.
Good Luck.
Good Luck.