"Secondly, a safety, certification, or whatever, is largely a joke. In most provinces ‘certified’ means the horn works, and that the vehicle has four tires and four brakes and a windshield. You can even safety a car without an engine, if you like. A safety is in no way a guarantee that the vehicle is reliable, or won’t break down. It simply means the vehicle has met some very minimal standard that it’ll go down the road without falling apart like Chinese patio furniture."
As I'm in the process of selling my car, I did the safety last weekend. The certification, if done at a reputable shop by a responsible mechanic , it's a little more than what the above paragraph tries to convey.
First, suspension and steering are in fact checked as part of the safety, plus many other parts like brake lines, fuel lines, fuel tank, body integrity, not to mention the brakes. While not all-inclusive, a properly done safety certification should still mean something.
I think the fine line comes to differentiate between worn but still safe versus not safe at all and this is why an independent inspection is in order. As a buyer, since you probably don't know the shop/mechanic who signed the safety certificate, you should do your own inspection at a trusted entity (a potential buyer asked me to do that and I had nothing against it).
However, no inspection is a "guarantee that the vehicle is reliable, or won’t break down". The most you can reasonably expect from having a trusted third-party inspection is that the things are not already broken or about to break.
BTW: I had to replace a torn bushing on the trailing arm to pass inspection. The inspection was done at my servicing dealership by the same mechanic that mostlly serviced my car over the years and I reasonably trust. I asked him to give me a honest report, beyond safety, so I know if there are other issues that require immediate attention. Fortunatelly, there were none so I feel comfortable taking the car to the buyer's mechanic.
