Copied and pasted from SFI 38.1:
9.0 PERIODIC REVALIDATION
Test reports with successful test results must be submitted to SFI at least once every 12 month period following the date of the initial design validation test for each model of Head and Neck Restraint System manufactured by the participant. If multiple test reports are required to obtain all test results, then the earliest test date shall be used to determine when the periodic revalidation reports are due. Also, SFI shall retain the option to conduct random audit reviews. SFI shall purchase the product on a commercial basis and test for compliance to the specification. The submitting manufacturer shall reimburse SFI for all audit costs.

10.0 CERTIFICATION OF COMPLIANCE
Upon demonstration of successful compliance with all the requirements of the specification and the self-certification program and upon entering the licensing agreement with SFI, the manufacturer may advertise, present and offer the Head and Neck Restraint System for sale with the representation that their product meets the SFI Specification 38.1. Continuing certification is contingent upon the following additional considerations: (1) the product shall be resubmitted for testing following any change in design, materials and/or methods of manufacturing not specifically excluded, and (2) periodic revalidation test reports are submitted when due to SFI.
SFI claims they will purchase the product and re-test it periodically. Whether they actually do that or not... I have no idea. But I would think the threat of it would be enough to keep most manufacturers in check.
Devices must also be recertified after any changes in design. How well that is enforced, I have no idea.


I am very interested in what restraint you end up with!
Me too! :-? It turns out, we might have no say in the matter afterall...