Valentine is your best bet.
There was a real good thread on this at Escape Central a year or two ago. Laser is aimed at your license plate, the most reflective part on your car. The policeman aims the laser at the license plate and with an instant on gun, the burst may be quick enough that you don't get any warning even with a high dollar detector. His solution was to remove the plate and replace it with a color copy (no sparkly reflective material). Put it under a clear plastic cover and it would be very hard to notice.
