When was the last time it was serviced cbrr3?
Did an oil change on mine at the weekend inc engine flush (fuel filter and sedimenter changed/cleaned about 2 weeks ago) and it feels so much better to drive now. Oils were only changed in Feb/Mar time but not by me so wanted to make sure.
Next job will be diff and g-box oils
Other things you might want to do:
Clean the intercooler if you already havent.
Fit an air filter a new element is about £3 but not sure if you meant someone has removed the whole surround.
Fit a decat pipe about £17 but apparently makes a nice difference to power and mpg.