1. Mecanum Wheels
2. LEGO / TETRIX / MATRIX adapters (not just to connect pieces but adapters so different systems can POWER other building systems. For example like a modified TETRIX axle to have a cross on one end to fit LEGO pieces onto it.)
3. Motor mounts (or combo motor mounts to connect motors together without taking up too much space, and better support.)
4. Custom gears (maybe not necessary with MATRIX but TETRIX gears in my opinion are way too big.) including worm, rack and pinion so teams don't have to use chains & sprocket (which is a good alternative) to achieve linear motion
5. Custom size sprockets
6. Better axles (It's part engineering too stronger axles wouldn't hurt)
7. Custom wheels!!! Especially if your team owns some special LEGO tires that no one else have
