Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. With a text editor, edit the "kitt_data" file in the "\davilex\knight rider\data\vehicle" folder. Edit the value of "DirectionRatio" line under the "TURBO BOOST" heading. The default value is "55". Changing it to "65" should enable you to jump most walls or obstacles without having to use the crates. Changing it to "70" to "75" will get you to the rooftops without a problem.
When you get to "Last Knight Standing," where you have to shut down KARR, use the following trick to defeat him easier. After the dialogue between Michael and KITT ends and KARR starts coming towards you, quickly turn right. You will see a electric box with a poll sticking out of it. Either drive through that or Turbo Boost through. This will set off the electric static, like from the previous mission. Turn around and wait for KARR to drive through the static. This will damage KARR greatly. If timed correctly, you can Turbo Boost over KARR and the static. After turning around, KARR will most likely turn and go back though. Keep doing this and you will defeat the Knight Automated Roving Robot will little, if no, damage to KITT.