Hi..the blind spot warning on my Forester with 3,000 miles recently is working only occasionally..both driver and passenger bsw mirror lights often fail to illuminate when vehicles in the adjacent lanes pass by...this problem just started in the last week or so and prior to this the bsw system worked great..there' s no obvious sensor or bumper damage/dirt and the bsw system is confirmed on... being an intermittent problem, I wonder if it could be an electrical glitch ..I took some video to show the dealer in case the system decides to work fine when a tech checks it..anyone have issues with this system? thanks..