First follow signs for trafford centre when u come off motorway. (Easiest way to get to the outdoor car park is to get off the M60 at junction 9). Then once near the complex head for festival village. Just thinking might be better parking in the further away of the 2 carparks cos it'll be less crowded.
The Car park near where the new John Lewis is being built (where i saw you Chase). Its replaced the Festival Village for those of you that know it.
Basically as you approach the village area you come to a roundabout, right takes you in the direction of the trafford centre entrance itself, left takes you away from it. Take the left.
