How much of a stretch are you talking about, and are you doing it for clearance issues?
One con is when hit a pot hole or something else, you can get a flat via loosing the bead on the tire, damage the tire, and also damage your rim, but that's for more extreme stuff like a 225/40 on a 10.5 inch rim.
Personally I like seeing a wide tire under a car with a nice side wall like a 305/30
Make the car an extension of you, and your personality, and give zero sh!ts about what other poeple think, it's your ride.