My guys, 5 and 2.5 yrs, are addicts.
We generally have the garage off limits, so going in there is a treat for them (often they disappear and we find them in there).
My older boy, Max, could name every make of car as we walked down the street by the time he was three (whether here or in the US). He lords the fact that he has gone for COPO rides over his younger brother and managed to convince my uncle to take him for a terror ride in his W-31 when we were in Vancouver a while ago. One of his most memorable experiences was an afternoon visit to the SCW a couple of years ago -- when Joe's Harrell Camaro was later featured in Chevy Rumble he looked at the pictures and correctly identified it as "Joe's car". I took him to Donuts Derelicts when we were in California and he loved it. I swear if he could reach the pedals he would be able to drive.
Jake is similar - he used to use a SCW can cooler on his milk bottle and thinks everything good in the world comes from Goodwood (the estate where the Festival of Speed and vintage car racing events are held). Whenever we go anywhere as a family he makes sure I'm driving because my right foot is a lot heavier than Mom's.
Both boys are totally enamored with WWII fighter planes at the moment, so maybe they would rather I had a P-51 than a ZL-1, but I'm sure they'll come around. I can't wait for them to be old enough to go to Collinsville