"Bilal said that I should check out a Silas truck stranded on a highway. It's probably filled with useful parts we could use to maintain and upgrade my car."
After arriving at Bilal's Tar & Dust Workshop and speaking to Bilal he will mention a Silas struck standed on a highway which he claims will be worth the effort. Head over there. The highway is located south of Bilal's workshop.
At the truck itself, it becomes clear that the truck's driver is still alive and armed:
Crane:"Oh shit - sorry! I didn't think there was anybody here!" Trucker:"I'll be ya didn't! Thievin' little sumbitch!" Crane:"Well relax, it's not like that! I was just looking for some parts to fix up my ride, I wasn't going to steal anything!" Trucker:"If it's parts ya want, it's parts you can damn well buy. Jacob Greaves is the name." Crane:"Kyle Crane." Trucker:"Good to meet ya, Kyle Crane. Now, listen here: these parts is mine. You want some, I'll sell ya some. But ain't nothin' for free." Crane:"Understood."