Good news, i figured it out!
Il write the numbers i used for future reference for people.
So after ticking the Quat option, it did indeed stop doing a reverse flip, but then it would rotate 180 degrees, then reverse the direction for 180 degrees ect.
Took some Time to figure out, but it ended up being to change a single number for the rotations, il list them below (To make a rotation, it takes 4 key frames)
Rotation
X Y Z
180 1 -180
0 -90 0
0 0 0
0 90 0
After you can get the propeller, tire or whatever people use to rotate 360, just copy.paste these 4 key frames and it should work perfectly fine.
Thanks for helping me out!
Edit: Formatting broke the degrees for rotation, uploading image instead.
