Button under accelerator, does what?

So, i have recently discovered a button under the accelerator, but i have no idea what it does?
When the accelerator is fully depressed it pushes in with a click but as far as i can tell it doesn't seem to alter the cars performance.
As my car did not come with a handbook i was wondering if anyone could enlighten me please?
:confused1:

Many thanks.
 
As said, if you have the limiter set it allows you to go past it (such as overtaking on the MWay)

However it doesnt disable the limiter, once you go back under your set limit the car will stop accelerating any furthar.
 
It also serves to annoy the hell out of you when on the move ( or it does me anyway :tongueout: )
 
yeah sorry jaxx i forgot to mention that lol it flashes the speed on the TC untill u go back below it then turns the limiter back on. tbh y what is the speed limiter for anyway?
 
Wow, I'm learning every day.
Thanks a lot Gents.

P.S: I'm a little disappointed that its not a nitro boost or rocket launch button...
 
They have it on merc Cl63 amg called a kickdown switch when u floor it it selects 3rd gear and it goes like ducking rocket lmfao