Firstly it does ruine the asthetics of the aero kit! Secondly they are there for a reason. to deflect air-water-stones away from places it will damage the car.
I knocked one of mine off and broke the other. You'll just have to learn to deal with it and when they break buy a new set for £14.00

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There was one guy on here that said he filed the inner edge of them away abit that stopped it.
http://www.mini2.com/forum/3328096-post6.html
Joe