I found getting through this puzzle required you to have the remote control to hand at the right times AND
required you to act quickly.
When you enter the tunnel where the aligator lives, you have to first make absolutely sure
that Glottis has driven the car into the tunnel as far as it will go.
Then use the remote to lift the car up.
Then jump out onto the ledge and go to the ladder at the other end.
This is where you must act quickly.....
Start down the ladder and the aligator will turn round to face you.
Now quickly go back up the ladder and use the remote to lower the car onto the aligator's tail - whilst it is still facing you
Hope that helps