I DRIVE A PEUGEOT 307 HDI 2005, I REALLY BATTLE TO GET A LOCK ON IN THE CAR, WHEN IT IS CLOUDY I DONT GET ANY LOCK, YESTERDAY I WAS ON THE ROAD 2.5 HOURS WITH NO LOCK. wHEN I GOT IT IT LOCKED VERY QUICKLY BUT IN THE LAST 2 WEEKS IT HAD BEEN VERY DIFFICULT TO LOCK ON, IF AT ALL. DOES ONE HAVE TO LOCK ON BEFORE STARTING TO DRIVE, WHATS AFECTING IT AND WHY IS IT NOT LOCKING ON? DOES ANYONE ELSE HAVE THIS PROBLEM OR ADVISE

THX