Sorry to be different, but I always use that bottom fixing on my rally cars with a Loctited stud & Nyloc nut..
In addition I make the rest of the exhaust from the Y-piece back one welded assembly.
The Y-piece is clamped in place using the normal clamps, but the lugs are vertical upwards on the inner and horizontal on the outer so that they wont break if they hit the ground. Then I drill upwards through each of the clamps and tap each 1/4" UNF and put two stub-bolts in using Loctite.
At the rear, I have the big choc-block at the front of the sub-frame and 4 cotton-reel fittings, two vertical and two horizontal with a strap across the underneath of the exit pipe.
I have dented exhaust pipes, flattened Y-pieces and damaged rear boxes, but never lost an exhaust (yet!).
I also have an 'ultimate engine steady'.
By the way, on cars with a remote gear change, the remote casting has a 5/16" UNF hole at a 45 degree angle for a clamp, but it only seems to work with a single standard pipe.
Edited by Cooperman, 22 September 2021 - 08:53 PM.