SWEEET!

I was thinking of similar on Vic Euro Plates e.g. V-IPGTBBB
I'm grateful to Mark for remembering my interest in these all the way back from when Nick had them FS.
I had asked Nick if these were more Gentleman or Hoon and I can now confirm that finishing up a 3" TBE, they are in the latter category, yet with an absolutely delightful tone.
The WRX STi sedan quads are of smaller inlet: 2.25? Less baffled inside probably than stock Lib muffs - I'd describe them as an enhanced steathback muff.
They are super quiet on the freeway and at idle and have a well regarded higher pitched wail on and coming off the gas.
The PROVA muffs are akin to the PhatGT muffs & etc, 2.5" inlets and a more straight-through than baffled can.
Thus they have the deep bassy throb on idle (and on Freeway cruise alas) rising to a very rich multi-tonal wail both on the gas and on the overrun.