Modifications & Warranty esp. in Canada

D12,

Not sure about the exact Canadian equivalent of the Magnuson-Moss Act, but the effort required to legally force a dealer refusing to perform service under warranty often requires time and monetary investment that are close to the cost of the repairs themselves.

The dealer won't have to prove your component caused the problem. He'll likely simply refuse to perform the service under warranty. The cost of hiring a lawyer plus a technical expert to prove that the aftermarket item didn't cause the failure runs in the few thousand dollars fairly quickly, plus the time you will need to invest to proceed with that route, and potentially renting a vehicle during the dispute.

In the end you could win and force him to perform the work. But actually, did you win if you consider the time and money needed to win?

Moreover, in difficult financial times like we currently have, expect to see budget restrictions and cost cuts. I would expect Toyota's regional inspector (the one that approves major warranty work) to be taking a closer look.

*Edit*
: The closest equivalent to the US M-M Act are the various provincial Consumer Protection Acts, therefore they'll vary from province to province.

Just took a look in the "Owner's manual supplement"
page 12
What is not covered:
This warranty does not cover damage or failures resulting directly or indirectly from any of the following:
-Modification, alteration or tampering, disconnection, including installation of non-Toyota Accessories

So, in short... aftermaket mods are a risk, and you can eventually win a case, but it might cost you as much than the repair (or more).

Back when I had a Subaru WRX, we had an internet club and we internally publicized which dealers were "mod-friendly" and which were not mod-friendly.
I think I hear that eventually the mod-friendly dealer in our area started getting attention from Subaru's regional inspector (probably simply a statistical comparison) and then it became more like the other dealers.

 

My local Prius dealer had a new owner meeting where they discussed, among other things, what the problem was with the EV switch. The basic comment was that EV mode wears out the traction battery faster than not using it. Because of things like the long warrantee requirement (150,000 miles) in California, Toyota decided to not offer the EV switch in that market. They made the judgment call that the extra warrantee battery replacements were not worth the sales value of having the EV switch as a feature.

The Toyota mechanics know about the EV switch, and they also know that a properly installed one isn't going to cause any problems. But it does contribute to the wear on the traction battery.

I think we need to regard the traction battery as just another wear item, like belts, tires, brakes, and all the other items that have to be periodically replaced. A car that is driven aggressively will wear out the tires faster than one that is driven slowly. If EV mode is used extensively, then the traction battery is going to wear out faster.

The real question is how much faster does EV mode wear out the battery? Obviously not so much that they don't offer it in markets outside North America.

I've got an EV switch, and I use it whenever I want the quiet function. I really don't expect such usage to destroy the battery too quickly. If such usage causes the battery to fail at 150,000 miles instead of 160,000 miles, then I'm not going to harass the dealer about a defective battery. Now if it fails at 50,000 miles, the EV switch is history and the dealer is going to have a warrantee claim...

 

dr12,

For the subwoofer, maybe you could look into one that could easily be removed without leaving a trace. Just a suggestion.
Also, as RobH suggests, maybe you could install an EV switch but make arrangements to be able to remove it if you had problems and wanted to make a warranty claim. After all, that switch is OEM in Japan (and Europe, I believe) so it's not like if you would install a turbo charger, or some other aftermarket mod.