Unity 4 assets to Unity 5

I was wondering if anyone has a guide or pointers to get unity 4 physics based assets working with unity 5. Car controllers, vehicle controllers, hand controllers, rope controllers....none of it work when I import into unity 5. Hand and rope controllers go all bonky, the joints they control leap all over the place. Vehicles tend not to get off the ground -- but sometimes once they are moving they are ok, other times they just won't move at all. There must be some value(s) that can be tweaked without rewriting all the scripts? Please help! The physics in unity 5 is freaking awesome, it would be a shame to have to pass it up for subpar u4.6 physics just because I cant get some assets to work.

Hi,

We're going to polish up the upgrade guide for Unity 5. However, it must be said that some of physics in Unity 5 is not compatible with Unity 4.x and needs to get re-tuned.
Areas like ragdolls and vehicles are receiving some love right now.

Awesome thanks for getting back to me. I have to say tell you guys that Unity 5 is so awesome I'm willing to scrap major elements out of my project just so I can use it. Calcs seem to run about 4-5x faster even in beta!