Made it to sub-10. Repaired the car and refueled it before starting my runs to avoid time loss on that, and correctly did the buggy drop off unlike my first run for the nuclear codes. Main issue I still need to resolve is the first jump being so tight due to the zone to activate the mission being so small. There's also a bit of an issue with me using the roads instead of going off-road to get the transport key.

Mod Note: ReUploaded