the lumpy idle may be the throttle body needing a reset, if you have AUM (and may work for other codes) then its easy, open the bonnet and turn the ignition onto the second click, make sure you leave the drivers door open when doing all this... put your ear next to the throttle body and you should be able to hear it tweaking its self, then start the car.
if that dose not work the take the pipe off the TB and look to see if you can see and dirt on the TB is give it a clean and repeat the process. should sove the problem 
hope this helps
A throttle body reset?! Please explain the logic there...
My guess would be a coilpack but as I said before, first step would be to scan for fault codes.
im not exactly sure to be honest, mine was a bit lumps and saw a post on here that doing that would work and it did for me, just trying to pass a helpful tip on is all, may be 100% wrong and i just go lucky hahah
