Yes,
1.
Extend the end of the axle with the splines so the HUB grabs more of the axle splines. Reason is if the axle moves out a little the only thing ON SOME that stops the axle from coming out is the "C" Clip. So when it moves out the HUB end is wobbling on the axle and ruins the hub splines. Maybe they can add a Bearing that rides on the side of the ACTUAL WHEEL BEARING and the 'C" clip right up to it so the AXLE will not move out.
Better Idea I think is EXTEND the WORM GEAR SLEEVE out onto the AXLE and have SETPIN OR SCREW through the WORM GEAR SLEEVE and into the AXLE that way the AXLE will not move out at all and have a access hole in the TUBE to take it out to be able to pull the axles out.
That was one of the FIRST things I tried to do I have a DRILL HOLE about HALF INCH next to the Differential but then I found that the WORM GEAR SLEEVE only extends to the outside edge of the Differential Case.
I believe now they all have the FLOATING RING about 4 inchs from each end of the axle tube held in place with two bolts and they welded a piece of pipe right next to it to stop the axle from moving out further.
Back in 2009 when they first came in to the US when I bought two of them I had a lot of trouble with the axle moving out and the wheels wobbling. I complained and they wanted pictures which I sent them and 3 months later they Added those Floating Rings and sent me a complete UPGRADED axle.
2.
One big pain in the arse is the FLOAT in the TANK it is so CHEAP it falls apart I have changed it 3 TIMES. They should make the FLOAT out of COPPER or something BUT NOT PLASTIC.
3.
For the US CHANGE the SPEEDO to MPH NOT KM/H, Mine has KM/H on the outside and tiny BLUE inside for MPH you cannot see the numbers especially with the RED tint glow. At night you can see but not in the bright sun. Or have some way to change it or a Decal to overlay it or something.
4.
How about a more powerful motor I think they at least need 200ccs the trikes are heavy.
5.
A little wider track in back
6.
Make the tanks hold at least 4 gallons. I cannot complain about mine because mine is in front and holds 4.7 gallons.
7.
How about a ACCESS DOOR in front of the VALVE COVER to make it easy to ADJUST the valves and change out the plug.
I think that is it for NOW (HAHA).
I think they should work on the AXLE part that causes a lot of problems for the CUSTOMERS especailly the ones that are not mechanically inclined.
As for the REVERSE the 150s are really easy to push around I never use the Reverse on mine and I have it adjusted and it works. But when I first got it I used to use it and found that the CABLE STRETCHS and then you have the gear meshing problem inside.
To help fix that to have some forgiveness either way when adjusting have THE GEARS it meshs with WIDER.
Right now it takes maybe a 1/4 of an inch either way and if your NOT right on the gears do not fully mesh and you get the JUMPING AND SHUDDERING and if not adjusted will ruin the gears.
Alleyoop