I went stage 1 on our A3 2.0 TDI a couple of months ago and went with a K & N panel filter. Overall the A3 is night and day much better . Picks up really quick considering its diesel and pulls like a beast.
No doubt the Revo intake will make a difference but £300 , that's a lot of money . I can't see you getting a huge performed increase to justify that money. I mean that's what I paid for the remap. I'm sure you'll get plenty more induction noise but only slight bhp improvement.
Personal choice really mate.
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