Just posted in the newbie section as I pick up my RS6 on the 16th so cant wait

Everyone has said get it remapped by MRC? what are the costs of this roughly? also can you di it without changing the exhaust? I am going to at some point but was wondering if the oem exhaust is very restrictive and no point in doing the remap until its changed?
Also anything else to look out for?
Cheers
Mike