RE: Why are cars & engines designed with side venting exhaust?
are you asking why there are side exhaust engines or side exhaust pipes? if you are asking why side exhaust engines, then space issues, some engine placements are too cramped for rear exhausts, as for cars, get an exhaust deflector is you think it is that bad, as for rear exhausts off of the cars, nobody usually does it because all fo the suspension components in the way, it is much easier to remove exhaust parts when they are on the side and open instead of in the back and winding through the car