FWIW, I performed an experiment last night. I bought some of the 2357's (8.5W) outlined earlier in this thread and compared them to the existing 1157's (5W) on the car. And also bought a $10 LED to compare the 2357's.
First test = 1157 vs. 2357. Wow! What a BIG difference. No pics to post, but it was really, really noticably brighter.
Second test = 2357 vs. $10 White LED. What a POS! The freakin' white LED (12 bulbs) was noticably weaker than the 2357! Not only that, I think it was on a par with the 1157. Not all LED's are created equal and I learned that for myself with this test. The one LED I did buy is going back to the store tomorrow.
So, if you want a quick fix then go buy a pair of the 2357's (around $5 for both). They are hard to find, as most stores only stock one hook of them (mostly for the motorcycles guys) and always have tons of the 1157's. Good luck!
I can honestly say that my red car now has some considerably brighter red taillights.
-Dean