I only just noticed today on my way home from work that my copen seams very underpowered. It has a bit of a fast rattle coming from the turbo on acceleration. Feels like the car is cold and constantly experiencing turbo lag all through the rev range. Admittedly I have not had the money to survive it for a very long time. It has 105,000km on the clock. Is fitted with what looks like an aftermarket wastegate controll adjuster which has been there since I bought it and there are a couple of big pipes on the top of the engine that have been plugged up. Is very reliable otherwise and is great on petrol. Any ideas?