I had to heavily modify the plastic where the stock DRLs mount. The Tangos fit in the hole but you have to cut the back out of the hole using a dremel or something. The DRLs are for nothing but daytime visibility (visibility of you, not for you). Anything that is a fog would be an improvement and I know a couple have used the navigator lights and are happy with them.
Now, the cleanest and best route to go would be to by the SMA steel valance and mount some PIAA fogs or some other fogs in there. The valance is here:
http://www.h2source.com/201-103-4.htm
You could also do the valance and put some driving lights there since you have fogs already.
Here is a pic of the metal valance:
