Pick one and get it. Both are good and hard to tell which one is better. Just buy one and use it and when it's gone (a long time!) then buy the other one and see which you prefer. That's what I did and would up sticking with 303 because it's great on the dash and all the plastic on the doors and around the roll hoops which Raggtopp doesn't do. Protects from UV rays and keeps dirt and dust from sticking and doesn't make things really "slippery" like armor-all does.

For just the top, can't go wrong with either one......

 

They're both good products. I regularly use both. 303's more versatile if you're set on only getting one. 303 may be more likely to streak if you don't apply it correctly. Raggtopp seemed to bead water a bit more to me.