original rear bumper and m3 rear bumper??

[chillselalu]

hello all sifu....need to ask u guys something... can i buy the defuser only and attached it to the original rear bumper of my e36 rather than buying the whole m3 rear bumper??? both bumper looks the same...what differentiate the original and the m3 bumper is the defuser...is this a good idea.....or both bumper are totaly different in term of size and etc??? need info about it..appreciate your help...tq