Search multiple coloumn with multiple field

[eluser]harris_priambudi[/eluser]
[quote author="Tominator" date="1338989435"]Just change 'or' to 'AND' [/quote]
I was try that...
but it make the search suggestion will not flexible

if I choose the dropbox
car_name = x
car_colour = blue
car_horsepower = null

it will no data appear..
what I want is will appear some data which
have car_name = x, car_colour = blue, and horse_power = "any"