The fuse bypass switch that would be a fit for your 2008 Pontiac G5 is the Roadmaster FuseMaster, part # RM76511. This will allow you to flat-tow your vehicle without draining the battery. This does not have to be removed when you want to do normal driving.
I have attached a link to a fuse bypass being installed. The vehicle is different than yours, but the installation would be similar and will give you an idea how this is installed.
In case you do not have all of the components needed... view full answer...
The most cost efficient option we have for a trunk mounted bike rack on your 2008 Pontiac G5 is the Hollywood Racks Expedition 2 Bike Rack # HRF6-2. This is a confirmed fit for your vehicle with the spoiler and will give you the stability and support you are seeking without causing any issues with your spoiler. The hub has interlocking hubs to ensure strength and durability and the 6 straps will keep the rack in place.
I recommend using a lock like # e98891 and anchor # 298-BA0020... view full answer...