Ok there are a lot of HIGHLY modded Grand Prixs on this forum. I would like to take the chance and make a thread about which mod you think is the best mod you ever did. It can be performance based or appearance based. Just which mod would you for sure do again if you had it to do all over again.....Include cost and difficulty. And a location as to where someone else might go for such a mod. Also if performance based be sure weather or not to note if it is for NA or SC applications if necessary.
I don't have many mods myself but my favorite one so far has to be the HIDs. Those things helped the night vision soo much it is amazing. They were pretty straight forward to hook up. And the cost was reasonable. I only spent $80 shipped for 5K BiXenons. I got mine from VVME.