Crashing Cars

Here is todays puzzle. If you think that you know the answer, please post it in the comments section.

There is a blue car driving east at 35 miles per hour. Directly east of the blue car is a red car driving west at 45 miles per hour. the front bumpers of the two cars are a half of a mile apart. In between those cars is a silver car that is 14 feet 8 inches long and is driving east. The back bumper of the silver car is 500 feet away from the front bumper of the blue car. How fast does the silver car have to be going for the blue car and the red car to hit it at the same time? Please give your answer in miles per hour and round to the nearest one hundredth.