Does it drain from the gutter spout, or the "middle of the gutter"?
If from the spout, I have used a 1/4" cotton rope held with a clothes pin with pretty good success. Just use a small stake at the ground to control the drip. Another member (pretty sure here, but maybe on RV.net) uses 2 pool noodles. Slides on onto the spout, the uses a short piece of 1/2" pvc pipe to connect the two noodles. Not sure what you may come up with to get the drip away further, but hopefully these couple ideas help.
And I try to cheat the left to right level a 1/2" lower on the drivers side to eliminate this. But I also try to cheat 1/2" lower to the front to help keep water in the tub when taking a shower. Our tub/shower opening is to the rear of the trailer.