With a MP3 400, you can't get your center stand to clear it to allow putting down your center stand, when trying to put the turn-a-bike SADDLE under the bike in the way the directions tell you to.
You can't drive forwards onto it with the SADDLE turned 90 degrees, to where the SADDLE's deep valley in line with the line of your tires. Again, center stand fails to clear!
But, you can get your back wheel on the SADDLE's, by backing your bike onto it so that your rear tire goes through the deep valley on the SADDLE. This is the only way I've found for it to work with the MP3 400!!