To fit a pipe, rotate the cylinder down to the 8 oçlock position. Now the pipe will run straight down the fuselage.
Like Dick said, Europeans are not as spastic about using nothing but in cowl mufflers. We like the power that better muffler systems provide.
Canisters can be very good, but will never beat a good tuned pipe setup. In-cowl mufflers are way below par in the power departement.