Uh, anywhere pretty much.
PIAA makes good bulbs, but if you're looking for really really blue, go with someone else.
The cars look real cool with just the city lights on with the park lights.
I've tried, red, green, blue.
www.autobarn.com for some city bulbs that are very very solid colored.
And, yes that pic worked for a while, but I guess the address for my pics are dynamic. They don't stay working.