Europe has a draft standard that they're working on. ADAC in Germany has a SI test protocol but it's a fixed door method with nothing done to simulate intrusion or the forward velocity component present in most real-life side impacts. I don't place much value on ADAC's SI test for those reasons.
Currently NHTSA is working on our side impact test methodology and we hope to have some more info on that in the next 6 months.
Currently, the most thorough and demanding side-impact test (to my knowledge and in my opinion), is the Dorel-Kettering test. I know Dorel was hoping that this would be the test that NHTSA adopted for our new federal standard but I'm not sure if that's going to happen or not.
Truthfully, deep side wings and anything that absorbs crash energy is going to help in a SI crash. I'm all for Dorel's AirProtect Technology and Britax's SICT (Side Impact Cushion Technology). Anything you can do to stack the odds in your child's favor during the most deadly type of crash is going to be worth the extra initial investment.
Just my :twocents: