Here is the full list of all 11 Doc Clock: The Toasted Sandwich of Time trophies - there are 5 bronze, 5 silver and 1 gold.
Destroy five robots in two seconds.
Perform a 540 degree flip in a vehicle.
Destroy a robot using a robot head.
Sound the bell ten times within ten seconds.
Collect 20 robot heads.
Collect 75 robot heads.
Propel your vehicle 150 meters into the air, using any means possible.
Sit in front of a TV for five minutes.
The gnome must be cast back into the fiery chasm from whence it came.
Pick up twelve toasted sandwiches.
Complete every level without using the time slider.