Well it really isn't that bad, for me I'll be running just the s5 engine electronics so the 3 yellow plugs I have coming off the ecu is really the only electronics ill be using, than ill just still use the SA chassis harness and should be fine still

It becomes a head ache when everything off those yellow plugs splice into ever other wire...have to go through the manual to find out the function of those plugs if you need them or not to just run the engine

As one going through a swap into a gsl, I can atest to the pita wiring. It is very time consuming. And i really wish I found a gsl-se gas tank so i didnt have to run a surge tank and two pumps. Finding space and creating brackets without the help of a welder is not so much fun..... certainly doesnt help trying to mount all this while car on jack stands with limited space.

Very good deal on the GSL-se you found. might want to consider making that the shell fr your swap.