First, you want to drill a small hole at the end on the crack. This will prevent it from getting longer.
Second, clean the heck out of it, mineral spirits and then acetone.
Third, force some Dicor caulk into the crack. Just keep forcing it in till it's "full".
Then cover it with the Eternabond. Should take care of that crack forever.
Steve & Cheryl + Zoey, and Ziggy, our furry kids.
2012 Forrest River Lexington 283ts
Toad, 2013 Subaru XV Crosstrek