Air Suspension
 

Is it legal to install an aftermarket air suspension into a car that does not come with it stock?

In short, yes....but the answer is complicated. You cannot remove any of the required suspension parts...eg shocks, springs etc and it must function so that your alignment is always correct, no part of your vehicle may touch the ground when the system is deflated, controls must not be accessable from inside the vehicle and the system must be approved for on road use. Not meet any of these restrictions and you are breaking the law. Probably get a #1 inspection order and towed off the road.

Division 7D — Manual Suspension Control Prohibition


Prohibition

7D.01 (1) A person must not drive or operate on a highway a vehicle that has a gross vehicle weight rating of less than 4 500 kg if the vehicle's suspension can be independently controlled by a person riding in the vehicle while it is being driven or operated on a highway.

(2) Subsection (1) does not apply to a vehicle equipped with a suspension controller accessible in the passenger compartment provided the controller is designed and installed by the original vehicle manufacturer at the time of manufacture.


You also may want to take a look at a Provincial inspecton manual to see the requirements to pass an inspection and see what parts you cannot remove or cut/modify.