Okay, I've done all 20 trucks, and here are my thoughts.
1. You're not going to get all 20 trucks in one piece. In fact, you'll probably get up to 7 alive (with the right combination of upgrades).
2. I didn't get all the weapons, nor did I get all the upgrades. However, from the weapons I did retrieve, I liked the Saw blade launcher the best. Combat shotgun is a must, and the squid launcher gave me a few chuckles.
3. The normal sized tires did a good job for me, so I'd recommend to stick with those.
4. If you want a challenge, do manual. However, if you want to do the run as fast as possible without complications, use automatic. When you're on automatic, you only need three fingers: right index finger to shoot, left index finger to reload (R key), and your left thumb to use spike tires.
5. You'll need three spike tires and I'll tell you why: when you get to the metal box blockades (there are three of them) it's easiest to mow them down with the spike tires rather than blowing them to pieces and exhausting your ammunition.
Those five tips pretty much will come in handy. You don't have to follow them, mind you; I'm just throwing them out there after playing this game.