Yes, ADR's are where it's at for airbags and their deployment etc.
There are two levels of legislation in place - one is Federal, the other is State/Territory. Simple tenet of law is that where the two conflict, Federal legislation will ALWAYS override State/Territory legislation. That is one of the basic cornerstones of our legal system.
ADR's (and such) cover standard vehicle compliance issues. As you can expect, not every single vehicle that gets registered for road use is inspected and approved. Manufacturers go through a process called "type approval". The manufacturers are then expected to build every vehicle to the same standard as the several which were inspected for the "type approval" for that range.
Then you have what is known as "low volume" or "secondary manufacturers". Think of such names as HSV, Tickford (or whatever they are known as now), and a range of "kit car" manufacturers, who use a donor vehicle which has already been type approved. There are differences between low volume and secondary manufacturers, but for the sake of simplicity, let's throw them in the same basket for this discussion.
These kind of approvals are at the Federal level.
Companies like ARB and TJM go through a process of endorsement which is similar. They create designs, which are approved in principle. Then the "in principle" designs are manufaturered and tested in real world. That is your impact or crash testing process. Following the successful process of crash testing, the (for example) bullbar is "type approved" for installation on X vehicle. That is a Federal level approval signifying that the device has met all applicable Federal legislation. Smaller manufacturers often can't afford to undertake the approval process, and it's not just a matter of thinking "she'll be right" and throwing a sticker on, because making a false declaration (that is, putting an approval sticker on when the approval process hasn't been undertaken) is a fairly serious offence. We're talking fines in the tens of thousands of dollars minimum, and the possibility of fairly decent jail terms. The manufacturers also have to retain all the evidence of undertaking the testing, and produce it to any authorised agency if requested.
No State or Territory registration authority can override that approval.
However your State/Territory registration authorities are the ones empowered to ENFORCE the legislation - whether that be State/Territory or Federal legislation. For example, back when I was a cop, I had powers under certain sections of legislation from NSW, the ACT, and also Federal... Generally they cover different things, but sometimes look lke they cover similar things, but from a different perspective. Can get complex, I assure you.
Anyway, back to the point. That is why the "big names" have the sticker which say's the device is ADR approved for installation on X vehicle, won't affect airbag deployment etc. Basically, makes the job a little bit easier if your local rego guy (who is the one responsible for enforcing the rules) wants you to prove that your bullbar is compliant. You see, your standard vehicle is "type approved". All good, now you can register it because although it is YOUR responsibility to ensure the vehicle meets all relevant legislation for being roadworthy, the manufacturer has done this on your behalf. But you want to install a bullbar. So you can either (a) select one from a "big brand" which is approved against the relevant legislation, or you can (b) have one made by your local expert welder and fabricator. In both examples, it's YOUR resposibility to prove that the modification (bullbar) has not affected the vehicle's compliance to all relevant legislation. In exampe (a), you have the sticke on the bullbar. In example (b), you have no such evidence. And the local rego people have every right in the world to deem your vehicle unroadworthy until YOU prove your vehicle (in its modified condition) is compliant with all relevant legislation. The onus is on YOU, not them.
Now...there are companies out there who manufacture and sell bullbars which look very much like the bullbar designs of some of the big players. I'm not going to mention names... One of these companies even states that their bullbars are "airbag compliant". That would, in my opinion, lead the average consumer to believe that the bullbar is okay to fit on their airbag equipped vehicle. However I have inspected several bullbars from one particular company, and nowhere could I find a label stating that the bullbar was compliant with relevant legislation. I brought this to the attention of the owner of one vehicle equipped with said bullbar....he contacted the company, only to be told "No, we don't get them approved, but they will work with your airbags just fine". Regardless of the manufacturers claim, fitting that bullbar to the vehicle made it instantly unroadworthy.
That's one of the reasons the bigger players charge more for their bullbars - they have to recover the R&D costs.
Anyway, hope that helps with one example of why you don't have to have your bullbar inspected/engineered etc for approval, if the manufacturer has already done it on your behalf. If they haven't had it approved already - you would have to have it inspected and approved yourself. Other mods are the same - if they are "type approved" by the manufacturer - all good. If not, each person who wishes to fit the accessory or modification must have it inspected/approved themselves.
