"They really feared our trucks and jeeps even more."
I sincerely doubt the average German combat soldier "feared" our trucks and jeeps because they had little to no ability to kill them. German high command feared the US ability to mass produce weapons of war, but that's not what we're talking about here.
You're missing the point, MLeake.
Of course the Germans feared US artillery, they (just as our troops did) feared ANYTHING we had that could kill them.
What happens, though, is that when an army doesn't have an equivalent weapon to something the enemy has (the M2 for the Americans, the MG42 for the Germans), those items taken on quasimythical characteristics and there's more than a certain amount of dread associated with facing them.
Direct comparisons can't be made, so through rumor and gossip the item starts starts to be imbued with characteristics that it doesn't have, and legend based on fear develops around it.
"Hey Hans, that's an Amerikaner M2! It can shoot through 950 Nazis, and if the bullet passes within 5 feet of you, your head will exploden!"
It is, essentially, a fear of the unfamiliar and the unknown.
"Unless the History Channel is wrong"
Gee, that would NEVER happen!