ive never had a prob and dont know anyone who has, but it does make the handling feel a bit odd when you do a REALLY mental stretch like the above pics.

a normal stretch, like 225/40s on a 9.5x18, is fine and totally 100% safe even on the hardest test for tyres ripping off (ie drifting) and dont affect the handling. IIRC in the olden days (50s and before i think, before tyre choice wasnt as good) racers used to stretch the tyres as it stiffened the sidewalls, giving em better handling.

as long as you go to the right places tyre places are fine. with an extreme stretch like the ones i posted up you wont get em sitting on the bead normally anyhow, need to go somewhere with a cheetah to blast em on.
normal places wont be able to, and some retards from quickfit etc would prob tell you its dangerous, tho theyve never tried it.

with 225/40 on a 9.5 sort of thing, most are fine, but you sill get some gaylords saying its dangerous. i tell them to shut up and put it on.

and yeah, the volvo rocked. shame it was so rusty i decided to scrap it