They are most aesthetic than purposeful.... they do help to expell hot air from the engine bay (a bit) though.
They appeared on the original CSL nearly 30 years ago amoungst a mix of rubber bonnet spoilers, roof fins and huge (triple in some cases) rear wings. It also had the M coloured line from grill to tail
The 'batmobile' as it became know is now regarded as the 'peoples' favorite BMW of all time in europe.
I am glad that they chose to leave some of the styling cues in the past though.
<span style='color:blue'>"So my BM makes me a flash bastard? Then I guess you're just keeping it real from the seat of your nova?"</span>
<span style='color:gray'>"...and the home of the brave..... is bravey 130bhp from a 7 litre engine? 100bhp/litre or don't bother building it!"</span>
<span style='color:red'>"Aaahh the UK; where every road is jammed, under construction, poorly maintained and unfairly policed, at least we don't get over-taxed for it........ HA HA HA!"</span>