I followed Dr. Aruba's suggestion and changed to Xenon HID 9007 bulbs, without changing to HID system. They are a snap to change. The visibility is better, the head light changed from yellow to white with a blue tint, The improvement is small but noticeable, but worth the very low cost ($25). Of course I later found out you can buy the same bulbs even cheaper ($10) on eBay.
I went with DOT street legal 55 bulbs, the result should be even better with 80/100 power Xenon HID 9007 bulbs, maybe I will buy a new 80/100 pair and try them out, price so low anyway. Full HID system lights are annoyingly blinding to me when I am on the receiving end, consequently I don't want to do that to the others.
I have not change the 3157 DRL bulbs, , but I am interested in changing DRL to a different color just for the look. They cost $5 to $20 on eBay. I see there are green, blue, red available. Anyone tried them yet?
http://search.ebay.com/search/search.dll?MfcISAPICommand=GetResult&query=bulb+90 07&cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&ht=1&f rom=R10&currdisp=2&itemtimedisp=1&st=2&SortPropert y=MetaEndSort&BasicSearch=