yep one of mine favourite too
not cheap
http://www.ctd-germany.com/product_info.php?language=en&gm_boosted_product=Strosek-Heckspoiler&Nissan-350Z=Karosserie-297&Strosek-Heckspoiler_html=&products_id=1578&
why not change them for some higher K xenons.
Also they may need realigning http://www.350z-uk.com/topic/51852-how-to-adjust-the-throw-of-your-headlights/
BM's problem with Bilberry is he used it neat if I recall. It always should be watered down.
I saw some interesting vids on Carpro Iron X wheel cleaner. Fancy trying some after the bilberry has finished