Long exhausts are not uncommon. The exhaust is an important part of a car's powertrain, and its diameter, length, and even shape can all impact how much power a car makes and how efficient it is. Very often, a longer pipe - provided it's the right diameter to maximize flow, for instance - can improve gas mileage. Traditionally, the final length of tailpipe aft of the muffler is relatively long, with the muffler located centrally.
But Honda's new design proposes the muffler being located far to the outboard extremities of a car's undercarriage. That's because Honda wants to ditch splash shields on the exhaust and instead let the muffler double up as both an integral element of the exhaust system and a shield for the tailpipe to prevent water being sprayed up from the rear wheels, which could result in the hot exhaust pipe cracking as it comes into contact with cold water.
Traditionally, an automaker would simply install a splash guard over the section of exhaust at risk. But Honda alleges that such a shield is too heavy and that "in order to suppress natural disasters," the cost and weight of such a shield should be done away with.
Source: Carbuzz
