Talk to Bill Goldstein and he says:

"I really need the parts that fell off before my vehicle came to a halt... I would be forever grateful if you could find them for me. There should be three parts.

Hmm.. Let's see... Ah, the battery, the gearbox part and the drive shaft part."

Respond with "Of course, we need to get this baby running again!"

"Great I would help you search for the missing parts myself, but I've injured my leg and I'd rather guard my things if you don't mind. If you can, kill a few more of those pesky Traeskerons as well, that would make me even more glad."

Respond with "I'm on it sir!"

"The parts should be somewhere between here and the large tree near the waterfall. They might be hard to spot, and I can't really mark any positions for you... Good luck though, this should go well right?"

Respond with "Of course. What do you think!"

Need to visit 3 locations for car parts:

Vehicle battery - 54223, 60395

Gear box - 54547, 60182

Drive Shaft - 54532, 60025

You also need to kill 30 traeskerons.