Engine will not consistently start?

Hello, my 1999 Jaguar XJR will not consistently start. If I get out of the car and the key fob will not automatically lock the doors and I have to manually lock them--I know when I return the car will not start without a jump. When I attempt to start the car, the windshield wipers try to come on but can only move a few positions and stop in the middle of the windshield. The lights dim on and off, the seat makes clicking sounds like it is trying to move into position but can't. It even sounds like the blinker is trying to make blinking noises. It has been in for a complete service--new spark plugs, battery checked and new wires put on, corrosion removed. Of course the problem appeared solved only to reappear a day after coming home from the dealer. It will then only start with a jump. Help!