The only practical way I can think of is using a client-server architecture where the server is developed in Unity and the client in Unreal. The server would provide VPP-based vehicle dynamics and possibly generic physics as well.
We would provide support about VPP only, as with any standard Unity project that uses VPP.
The other possible solution, porting Vehicle Physics Pro to Unreal, is currently out of the scope for us even in the long term.