The IVA test (the assessment performed by the Vehicle Certification Agency) is the formality required to legally certify the car is roadworthy. I've heard / read about the fact that sometimes Caterhams can be marginal, particularly in the noise and emissions tests, and so elected to have the company present the car for testing. When this option is taken, Caterham personnel attend the test and, where possible, make on-the-fly modifications to help the car through the inspection process. For those reasons I chose this option.
However, the approach that Caterham take is to assess the car at PBC first in order to understand how much corrective work is required before booking an IVA test slot. The implication is that, although my car did not require much remedial work, there was a 4 week delay between PBC and IVA. During this time I asked Caterham to fit a full Paint Protection Film to the car - this seems to come highly recommended by existing owners to reduce the impact of stone chips on the paintwork.
Finally the IVA test day arrived and, although I was 400 miles away, at the appointment time (8:00 am) I found myself pacing like an expectant father in a labour ward. I was told the appointment slot was 4 hours but at 11:15 I got a text message from Dan at Caterham with a photograph of the certificate after a successful test.