Yes we have, i think it was at Ripon race course, i had the old 7 there.
My solution was to fit a 45 degree mandrel bend s/s, 57.15 OD 54.15 ID, i used a stainless steel clamp to secure this to the existing shortened tailpipe which was 54mm OD. I then fitted a suitable length of 60mm OD stainless steel tube onto the end of the mandrel bend. The 60mm tube was a good tight fit over the end of the mandrel bend. You can rotate the mandrel bend to get the right height and orientation for the exhaust exit. Mine is elevated to be a bit closer to the underside of the rear bumper than standard and when viewed from the rear the exhaust exit is about central with offside rear tyre. All bits available from exhaust parts uk online.
The side exhaust sounds a bit drastic and expensive, unless you feel confident about getting the Dremmel out and chopping a bit out of the wing yourself. Mind i do find the clatter from the throttle bodies enough soundtrack without the addition of a side exhaust.
P.s wish i could post photos, I'll try again
