here is a dumb question.... I looked on here for a while but couldnt find the asnwer...I want to get a shroud for my car it seems to heat up at lights and moving slowly... but when driving it cools down....however i dont know how big the radiator is... do you measure just the fins across., the whole radiator across, top to bottom, diagonal, i dont want to throw money away to find out i have a dif size radiator.... could someone explain what measurement will give me the correct number so i can buy a shroud?