No, it is static discharge. The only other part of the car that has the ability to shock would be the ignition system that fires the spark plugs. In order for you to be shocked by that, you would have to disconnect a spark plug wire and hold it while the engine was running, then allow your body to touch the car's engine ar frame. Often people will think it is the car shocking them if they inadvertently brush past a point where there is bare metal. For example, there is a diagnostic connector under the dash with a ground wire in it. Sometimes people get shocked in the leg by the spark jumping to the ground on the connector and they think the spark is because of the connector's electricity. Touching that ground wire is the same as touching any bare metal or fastener screw on the door as you leave the car.

It really is normal, about all you can do is look into the anti-static products. Something as simple as rubbing a fabric softener sheet (like you put in a clothes dryer) on the seat may make a difference, and then you will know for sure it is just static discharge. Try it on one of the seats and see. You might want to leave one seat untreated if you want to show it to the rep.

On my car I used to grab the door before sliding on the seat to try to prevent the static build up. That helped, but it would still bite sometimes. I never knew about the anti-static products back then.