DRIVING A RENTAL CAR AT 4:30 A.M. ON COUNTRY ROAD ATTEMPTING TO CATCH OUR FLIGHT BACK HOME. AFTER DRIVING APPROX. 20 MINUTES, HEADLIGHTS WENT OUT AND DASHBOARD LIGHTS. WE HAD NO VISIBILITY, ATTEMPTED TO STOP VEHICLE, LEFT PAVEMENT AND STRUCK A TREE. DURING OUR WEEK RENTAL OF THIS VEHICLE WE DID HAVE ISSUES WITH SUV LOSING POWER WHEN CLIMBING A HILL, BUT NOT A STEEP ONE AT ALL. SUV WOULD DROP AT LEAST 10 MPH WHEN DOING SO. NOT SURE IF THESE TWO ISSUES ARE RELATED AT ALL.