you will gladly hand over your hard earned money for a shot in the dark chance that he will get it right (LOL) then when he doesnt you want to have to go through the hassle of sending the product back and forth until it's done the way it should have been in the first place???? And to top it off it may never be done right and there is no chance of getting your money back???
Don't forget in the meantime your car is sitting there without out a plenum and undriveable(for most people)