Hi there, I´ve got a simple los santos ambulance to los angeles ambulance gmc paintjob for you.

Installation:
-open openiv and enable edit mode
-go to your vehicles folder (for example C:\Games\Grand.Theft.Auto.V\mods\x64e.rpf\levels\gta5\vehicles.rpf\
-backup your ambulance files
-after that replace the files.
-enjoy