Try welding with a mirror, top of exhaust pipe while still in car. The absolute worst thing to weld in my experience. I have destroyed many inspection mirrors.
Back when I built my 3 1/2'' dual exhaust , I tacked them after pie cutting and fitting , then pulled them down /off to weld up, been on the car for about 9 yrs------now way would I
try to weld in a mirror upside down !!
