i don't laugh at guys that are tuning their cars even if it is a 100cc car with 5HP
the 133 is a carburetor car but its hood id not on top of the carburetor so you have room to make a pipe and place the filter somewhere away from all the heat... i didn't look into the engine bay of a 133 so i can't recommend a location but i am sure you will come up with a nice place with lots of cool air
as for sound... i highly doubt that the 133 will produce anything similar to what honda's or mitsubishi's produce because of the very different engine design... but i am sure if you chose a good location you can let the engine breath more cold air and produce more power
MMamdouh