2009 Porsche Boxster squeaky brakes

I bought a used 2009 with 32,000 miles Porsche Boxter S that brake squeak.
I took it to 3 auto service places including the Porsche dealer, all stated brakes
are goood (pads etc.) the dealer stated it was common with the high performance
models to have brake squeak, even sent a YouTube video as why high performace
Porsche models have brake squeak. The dealer performed a hot test where they drive
it fast then brake to heat up brakes it worked for about 50 miles then and now
still have squeak. I even tried going about 50 mpg then lightly pressing on brakes
while pressing on the gas. Nothing appears to solve the issue.
Would you know of anything to could stop the squeak for good as it drives and handles
great. Embarrassing when stopping at a light with such a nice car with the SQUEAK!

The dealer is right, performance brakes squeak. The pads can be removed and a very thin film of copper grease can be applied to the caliper piston side of the pads and the edges of the brake pad backing plate to quiet things down, temporarily. It will likely come back because the grease will wash off.

Other than trying various brands of brake pads until you find a quiet one. I suggest looking for Porsche Boxster forums and searching around to see what other brake brands Boxster owners have tried.

But, you may have to learn to live with it if you want to keep the car.