Anasazi Sandworx Co.
Bacon Slab, Utah
There are three sets of conveyor belts in the arena, but the principle for all is the same - use them as ramps! You can gain access by shooting the buidings at the base - this itself gives you a wrench. The ramps facing each other are basically a quick way to get across the level - as well as getting the powerups suspended in the air between them. The third ramp is more useful - it lets you jump into the funnels on top of the factory (see below). However, the ramps are pretty weak, requiring only a few blasts to bring them crashing down.
There are two entrances to the factory, the easiest being to shoot open the front dorr and go straight through. You'll then be expelled from the chute, thorough the air into the middle of the arena. The second method is trickier, but will snag you an extra crate - you'll need to drive up the ramp that points towards the factory and drop into one of the funnels on the roof, before being uncerimoniously ejected as before. TO NOTE - there's an odd bug in the Dreamcast version if you drive through the front door in first person. You start coming out the chute (still in 1st person) but will never escape as the animation loops over and over!
You can call the lift with a couple of gentle taps on the machine gun - when it reaches ground level, drive in and it will start taking you upwards, where crates and powerups await. Unfortunately, it's quite feeble and if an enemy spots you, a well placed Interceptor Missile or two will bring it crashing to the ground.
There are numerous sand piles in this level, all of which can be reduced by firing on them (even the Mosquito will do.) Remove most of the pile and you'll be left with a powerup, often a wrench. Since this takes quite a while, it's best to wait until there's no-one around. To speed it up, you may want to consider using something like the Bulls-Eye Rockets.
Gates & Sand Blocks
The gates and fences cause something of a bottleneck - this can be closed completely by destroying the sand blocks, which come crashing down sealing the gate. When this happens, the only way through is to destroy the fences. This provides and opportunity to corner enemies, but if you're particularly accurate, you may even be able to drop a sand block on them.
Weapons & Powerup Spawn Points
The arena is raised around the perimeter, there are a lot of powerups here as well in the buildings and sand drums. In addition, this is a good vantage point to shoot at enemies in the lower level. Wrenches can almost always be found in the buildings at the base of ramps as well as in sand piles, but these often take long to uncover.