Generally we have not had issues when running a single wire thru the grommet in the firewall. In most cases there is room to get the wire thru without risk of pinching. If you do not have room and do not want to take that risk, I recommend making a separate hole and adding a Nylon Snap Bushing like the # SWC8052-1. This way the wire will be protected and you will not run any risk of a short. view full answer...
You can get four of the Thule N147 lock cores and as many N147 keys as you like but you'd need to order them individually because there isn't a way to get a 4-pack with a specific lock core number. So you can order four of the N147, and additional keys if need be, with the following parts:
- Replacement Lock Cylinder for Thule Racks and Carriers - N147 # THLOCKN147
- Replacement Key for Thule Racks and Carriers - N147 # THKEYN147 view full answer...