See who they bring in from motorsport companies as guest lecturers or to act as industrial tutors. They should have an advisory panel of people from industry and that may give some clues.
The other thing is to find out the CV for those you want to emulate. Look on company & team websites for key people, then see what their education was - Linkedin is a good source for that sort of info.
Also ask the departments about what people have done in previous years after graduating from the course. They'll not have comprehensive data on every person, but they should have a good idea if any of them now work in motor sports. Remember they want your money, so let them sell the course to you!
Edit
I've just done a search on LinkedIn. The results for Brooks has lots of motor sports entries including 3 people at F1 teams in the first 2 pages. Couldn't see any on Cranfield. However you'd need to be careful because some of the companies might be in the supply chain and you might not recognise the names.
- Go to LinkedIn, click on "Advanced Search" (top right)
- Type "Cranfield" in the"schools field"
- Select "Automotive" in the industry
- Repeat for Brookes