my car s4 n/a came with my ecu in the trunk box.
i was trying to figure out where it goes but need some assistance.
i searched and read that in the s5's the ecu is under a floor plate in the passenger side.
is this true for the s4's as well?

 

Same place. In the passenger foot well. Pull up the carpet and you will find a large galvanized plate. The ECU goes under it.

 

ok, thats what i figured but wasn't sure.
thanks.