I think you're right SearchinGirl, the CSU sign is before the Prospect exit, not the Mulberry exit. So she maybe has sort of compressed that area in her mind. So maybe her car was hit anywhere in between the Prospect and Mulberry exit. I was on both yesterday by the way. So, a shooter could have perhaps been located in that grassy, tree area between the trailer shop and the Motorcycle shop. He could be concealed there easily have escape either to the north or south as needed.
Look at the reflection in her vehicle photo that Forager posted. There are trees visible..