When I did mine, I was able to do both the left and right side garnish mouldings with the new rubber without cutting the rubber strip in half (where the little center mating piece goes). So mine is continuous, without any cut along the length of the dash.
The trick is, getting the rubber strip to stay on while you are actually trying to install both long pieces, haha. But it can be done with patience and rock-solid willpower to end up with a professional looking job.