As an insurance broker I always recommend to my clients to buy the extra insurance when you rent in Florida. Just because you have the coverage on your car here in Canada, depending on your Company it may not cover everything in the event of a claim ie: down time. Plus, if you buy the insurance & have a claim, your Company here will never know about it. If you use the Sef 27 endorsment to extend your coverage to the rental, then the claim gets charged to your policy here. Plus, I would ask what limit of Liability they have on the car from the rental company. I believe the limits start at $15,000 in Florida & if you have a claim that will not pay for anything. You can increase the limit & I would suggest a mininum of $1,000,000. If you have a gold card you usually get the extra coverage automatically. Everyone thinks they won't have a claim but remember, you are in Orlando where 90% of the people are on vacation & either don't know where they are going or aren't paying attention or worse - both!