This is a safe strategy for Crash Site on Perfect Agent, which gives times according to ability as usual. Most players should be able to get under 3:30 and some under 2:30. It has the advantage of being simple and easy to complete too.
First of all, you must have enabled the hoverbike on the previous level (Air Force One) by lowering the cargo bay. At the beginning, jump on the hoverbike and head back to where you started and on to the right. You should be in an open area with 2 guards and the distress beacon for Objective 2. Ignore this for the moment, and focus on the guard on the right. Take him out while moving and get a k7. Go over the top of the bit sticking up and hopefully pick up the president scanner on the move so you don't lose your speed. Go back through the right hand exit from the area and head for the beacon (Objective 1). Activate it from the bike, hopefully while still moving, and head straight on, following the edge. In the next little passage, run past the 3 guards (2 with k7's and 1 blonde with a sniper rifle) into the really big area:
1: The Fast Way - throw your final remote mine into the holeand detonate to kill the clone. NB: you must throw it towards the right of the hole, and at the perfect height so that it doesn't get stuck before, or on the low bit just in front of you. This can take some practise, but is essential to a fast run.
2: The Safe Way - take down the 4 guards in here with your k7 and shoot the clone from above. You can use this way too if you fail to do it with the mine.
When the clone has been eliminated for Objective 4, go backup the slope and continue along the path to the right. Take the 1st left and kill any guards here. Got to the end of this short bit and strafe out into thin air over the canyon. When you land on the other side, go right, and make sure to kill all guards you see, as they will kill you in a couple of seconds if you ignore them and don't time a run past to precision. Follow this path along the edge of the canyon around to the final open area where you can see 2 drone guns. Make your way slowly forward to the highest piece of ground and shoot just below the right hand drone gun, but above the rim of the dip with the DY357-LX and you should destroy the Skedar Ship in 1 hit to complete Objective 3.