To buy a car, which is the best one to opt for car loan?

I would suggest you opt for the fixed.
This way you will know exactly what you will be up for.
This is usually short term anyway.

I agree on the fixed. Not only do you know exactly what you've got, but since interest is down, the only place I could see it floating is up.

Depends upon the rate, if it is low then I agree fixed.