I have a 1990 SR5. I must admit that I love lights, I have all the lights on the front of my car rewired to turn on.
My fogs, Signlas (on as lights and signals now), Parking lights and headlights can all be on at the same time.
The lights are legal as long as the colour is not closer to blue, they have to be white. I have been pulled over twice for my lights but it was because I had "too many lights on the front of the car" instead of the bulb colour or wattage.
Check out my website. I thought of what you're saying, but looking at the inside of the parking light, you don't really have a lot of space to play with and the angle of the mirror surface is designed for one bulb only.
http://www.cardomain.com/member_page...page_id=257252