Mario Kart DS/Level 7

Level 7 in Mission Mode can be attained by getting at least a one-star rank on all missions before it. It is the final mission mode level.

Mission 7-1
It is simply a normal lap through Rainbow Road. The best strategy is to carefully do three to four power-slide turbo boosts across the big spiral. If you are good enough at turbo boosting, do five or even the full six on it. If you have any left after to do after the spiral, use the wide curves to do them. The only thing to worry about is taking a fall over the edge of the track. Other than that, it's a moderate-level difficulty mission.
 * Description: Perform 6 power-slide turbo boosts in 1 lap!
 * Course: Rainbow Road
 * Character: Peach
 * Time: 1 minute

Mission 7-2
This is a simple yet complicated race through Bowser Castle. There is a blockade where the normal path through Bowser Castle goes, so the path is now split in two, where two additional Thwomps are. There are two more burners at the spinning gear and the path there that leads to the balcony of the castle is blocked off, so the shortcut must be taken. The spinning bridge can be taken but is useless because the path it takes is blocked off. Don't bother to get on it. Each item box like in the previous race missions has a result of a mushroom, triple mushrooms, a red shell, and a star. Use the mushrooms or star to launch down the edge near the spinning bridge and onto the ground. Use them on the Thwomps if needed, to avoid the three burners, and even humiliate Bowser! Just keep calm and Mario will win the race. But the question is, was that a good thing, because Mario made Bowser mad!!!
 * Description: Reach the finish before Bowser!
 * Course: Bowser Castle
 * Character: Mario
 * NO TIME LIMIT

Mission 7-3
It's Tick-Tock Clock with an upgrade! The spinning gears and moving clock hands are faster and trickier to drive through, there are now three pendulums, which is a pain, so time it right, and a very fast shortcut. Hit the item boxes, because they contain three mushrooms. Boost across the four spinning gears with them carefully, then go through the next item box available and use the gear shortcut. It will take Donkey Kong further and faster down it, and if you want to get really creative, use a mushroom and get maximum speed! However, make sure you don't get on the wrong gear, because it will drastically slow down the kart. All the gears occasionally stop and switch directions, so look before you drive.
 * Description: Complete 2 laps within the time limit!
 * Course: Tick-Tock Clock
 * Character: Donkey Kong
 * Time: 1 minute and 30 seconds

Mission 7-4
Get the green shells out of the item boxes, three if you have none, one if you have any, hit the Goombas before they get away, and that as simple as it gets. A good idea is to not only fire shells point-blank but out at the group. You may get lucky and hit the farther Goombas. Don't hit them yourself, because you may spin out, and that matters when the Goombas here are running away quickly but akwardly!
 * Description: Use shells to defeat all 30 Goombas within the time limit!
 * Course: Mario Circuit
 * Character: Toad
 * Time: 2 minutes

Mission 7-5
This mission takes accurancy. Driving carefully through the track will allow a quick pick-up of the coins. The only real challenges are getting the two coins in two additional Podboo rings. It is very easy to complete the mission, not so easy to get a three-star rank.
 * Description: Collect all 20 coins!
 * Course: Wario Stadium
 * Character: Wario
 * Time: 55 seconds

Mission 7-6
THIS IS THE HARDEST OF ALL THE MISSIONS!!! All eight gates are lined up in a tight circle in the order 1-6-2-7-3-8-4-5. This means it takes two go-arounds to get them. Get a turbo-boost start to reach the gates and start going through them. Do not powerslide, because this risks crashing into a gate and wasting time. Quickly weave through the gates, drifting (NOT BOOSTING OR POWERSLIDING!!!), and this will allow at least a one-star rank. A three star rank requires good timing and a very sharp turn through the gates.
 * Description: Drive through all 8 numbered gates in order!
 * Course: Nintendo DS
 * Character: Mario
 * Time: 11 seconds

Mission 7-7
This is not a mission to rush through. It is a maze of crates that lead to ten of the coins. Use instead of  to move and use  to go left and  to go right (as mentioned before). Do not get in a hurry driving through the crates, because it may result in breaking a useless path through or driving out of the maze. The only major concern are the two burners. Time it just right and get the last two coins.
 * Description: Drive backward and collect all 12 coins! If you hit a burner, you fail!
 * Course: Airship Fortress- Burner area
 * Character: Bowser
 * Time: 50 seconds

Mission 7-8
Look at the map as you race through Banshee Boardwalk. Check to see which item box is real (indicated by a green square) and which one aren't (indicated by red squares out of a group. There are banana peels thoughout the track, so avoid them, because one wrong turn could send Luigi spinning not only on the track but into the water. Each item box has a mushroom inside, so use them before reaching the next item box. When reaching the haunted house go left, not right and use a mushroom over the small path that is crossable. This will allow a quick shot at the first item box there. Going to the right requires more time to reach it. There is also a wall of fake Fake Item Boxes where the second pole is, so make a second left. The rest of the item boxes are easy to reach before the haunted house and after it.
 * Description: Break all 10 item boxes while avoiding the Fake Items!
 * Course: Banshee Boardwalk
 * Character: Luigi
 * Time: 1 minute and 5 seconds

Boss Fight
Wiggler vesus Mario? Very strange. The trick to racing against Wiggler is to get the fastest and longest turbo-boost start possible and get the first item box underneath the truck. All the item boxes are either moving across the track and contain a star or moving underneath the trucks and contain a mushroom. Use the mushroom from the item box if you can reach it in time before the truck falls. If at any time you collide with a vehicle or Wiggler himself, you'll lose a balloon. After using the first mushroom, get the star from the next item box. After this, ram into the closest truck and get the mushroom from the item box underneath. Get the next item box in the vicinity and use the star in it once the current one finishes its work. Keep this up to stay ahead of Wiggler, because he's fast. Do not use the shortcut because it can actually slow you down and cause you to miss a truck or item box going by. Once Wiggler finishes his first lap, he will get a little faster and become steamed. After he finishes his second lap he will get ANGRY. This time, Wiggler will turn red and sprint to the finish line at his fastest. He will also take the shortcut on the final lap as well. If you can beat Wiggler to the finish, he will calm down but mope in defeat, and Mario will relish his victory. Now for his real challenge; getting a three-star rank!
 * Description Reach the finish before Wiggler!
 * Course: Mushroom Bridge
 * Character: Mario
 * NO TIME LIMIT

GREAT JOB IN FINISHING MISSION MODE!