On Threads and Gameplay
This is a trick I've used in other games, quite successfully, that allows RPing out stuff by a couple of characters when everyone else wants to move along. This jeep is a perfect example. The current thread is going to remain open after the "main story" thread is started. It will function as an out-of-time place for events to happen, but have limited or no impact on gameplay. The best example is equipment acquisition. I call the threads "Continuity Threads". They help maintain continuity between games, are canon to the game, but don't have a purpose beyond allowing us to do these minor details outside of the game-game. (If you scan some of the other games I GM/play, you might see several versions of these threads.)
You can go ahead and start telling the story of getting the jeep in the current IC thread. Pay the money now. When the real story starts, since you've already spent the money, you have the jeep in the main story. But in the continuity thread, you don't, and you get to finish RPing it out. Getting new cybernetics and have to undergo surgery? Continuity thread. Your character can be in the hospital for 10 months, but the game goes on. Does it always "make sense"? (Joe is 10 months older than Nate, now!) Naw. But this is a game, not a book, so I don't care.
Short version- go ahead and start the story of the jeep in the current IC thread.