I know nothing about lighting. Can anyone give me the low-down on these? I have a car with a bad headlight module (2004 A4 1.8T), and the cheapest I can get it is for $200. Is a module the same as a ballast? Seeing as how kits are $150, would this be the smarter route in comparison to buying a new module? How easy is it to install these kits. Also, I want something that won't blind people but a nice blue color (to match my car) would be nice.