I wasn't crazy about the faded lenses on my directional and brake lights. I checked out replacements online and the best I found was about $15 each. That's not too bad but considering I had seven lenses/lights to replace I wasn't crazy about shelling out $100+ for aesthetic reasons alone.
I remembered how well the Sylvania headlight restoration kit worked on my girlfriend's BMW so I thought I'd give it a shot. I tried it out on the front amber lights first just to see how it would turn out and I couldn't be happier. It's a very easy process and took less than 20 minutes for both lenses.
There are a number of different kits on the market but consumer reports rated Sylvania and 3M as the ones with the best results that last the longest. It's been over 6 months and the BMW headlights still look great.
I picked up the kit at Autozone for about $21 (the price of one light after tax and shipping).
Easy instructions are also on YouTube. Best of all the results aren't exaggerated.
Here are some before and after photos for your viewing pleasure.