When I took delivery of my SRT8 Core last May, will inspecting the car there was about a half pond of pebbles / rocks on the inside of the rim, car had 1 mile on it, we concluded that it happen during transport.
Ask Brampton Builder, I am sure they use salt on the roads in Canada, and whatever city in the USA it was shipped from/thru probably still has salt on the roads from the massive snow storms during this past winter. It gets everywhere, and as those snow piles melt, the salt makes it way into every puddle around. Your car has double galvanized steel, with an ecoat before it is painted, so you will be okay. Just drive it around on a really rainy day, that should rinse it off.
Wow... I was going to say that maybe the driver did a lil joy ride. I know a guy that hauls new cars for ford and that just what he will do everynow and then. Also there could have bee snow in the area and salt from the roads could have got on the car. It's the pebbles that get me.... As long as your ride is running well I don't think its an issue.
Many cars are shipped to Windsor from Brampton via transport for striping and other items. The place where they do this work is down the road from where they store the cars awaiting shipping. After the work is completed they are individually driven to the storage yard in groups and the drivers are shuttled back to pick up more. So when people say their car has never seen snow or salt...well..that may not be entirely true. When I went down there in 2010 to check out the upfit center before the pink ones hit the dealers, several Challengers with no plates left at once followed by a white van. There's pics on the site here of this that someone took. To them its just another car sale regardless of what the new owner thinks.
Back when I was a Car Jockey (many years ago) we did a dealer transfer with a city about 200 miles away. Traded one of our cars for one of thiers. Disconnected the speedo cables so no miles would rack up. Just kept pace with the traffic flow. This was for a major car dealership that is still around today.
I'm sure you can't do that with today's vehicles but you never know.