Possible Clues:

• Course study checks out if estate is running properly
• Vehicle try-out
• Try staying under 30 kilometres an hour in built up area - that's some way to go to trial
• Evaluation made by a car manufacturer (2 words)
• To sample track might be a relief from study
• Try out a new car (2 words)
• Each of those in 4 across will need one of these - the dealer might even suggest it
• Car and Driver assignment
• A check to insure that a vehicle is fit to be driven