Hyundai designs a Zombie Proof Car with Robert Kirkman

This is really just a silly Hyundai Elantra commercial where they also talk to one of the Walking Dead creators about his work. There are roughly 3 different versions of the car depicted, and none of them are feasible.

Of course no one would pick a compact coupe as the foundation for an armored car if they had any kind of choice in the matter (and if they don't, there's no reason to talk about what a great choice their only option is). There are a couple key areas in which this car really shows the limitations of the basic platform (a compact coupe): Height, Carry Capacity.

Basics:
An Elantra weighs about 2,800lbs unmodified (and roughly 3,500 - 4,000 as imagined), has about 150HP (not impressive numbers from a 1.8L engine), and has a sunroof roughly 4'8" feet off the ground.

Height:
The idea of a turret on top of the car for offense is great, except for the part where he's talking about a car with a height of less than 5 feet. The average person is about 5'6" with an arm's reach of at least an extra foot. So, the person in the protected turret is still likely in range (the hypotenuse of an arm reaching to this height would be slightly longer than the ~4'8" car height plus the roughly foot and a half of turret). Have you ever stood out of a compact coupe's sunroof while the car was in motion? There's not a lot of room in that car period, there's certainly no room for a person to stand in the center of it while it's in motion in a high stress situation.

Carry Capacity:
The Elantra has a roughly 900lbs carry capacity (this weight includes driver and passengers, plus armor and such). I'm going to assume the weight of the cow catcher is about equal to an average small truck snow plow (250lbs), and that it's for hitting zombies not clearing the road of vehicles, and I'm going to place a fair shot in the dark of roughly 172.5lbs for the rest of the armor (assuming 7 gauge sheet metal is ideal, and assuming 23 square feet will cover enough glass). So far we've got 477.5lbs of carry capacity for driver, gunner, passengers, and gear. Each person likely weighs roughly 200lbs which means the car has enough capacity to deal with a driver, a single gunner, and two moderately well stocked bags of supplies. Any more than this and the car will start to run into issues, a lot more than this (say, loading it up with passengers and gear) and you risk significant damage to the car's ability to continue driving. All of this assumes they don't want to beef up the rear of the car to allow the vehicle to be able to "safely" ram other obstructions in the road (in a demolition derby drivers drive, and crash into each other, backwards to protect all of the sensitive components in the engine bay).

Other:
The roman chariot style blades on the wheels of a car was tried in an episode of the tv show Top Gear and it threw off the wheel balance to the point of making the car entirely undrivable for any more than a mile or two. Also, just about the last thing you want to do when dealing with zombies is damage their legs because it's much easier to see a zombie walking than a zombie crawling (our soldiers crawl when they want to be harder to see in modern combat for a reason). The general purpose of a compact car is to be accessible (read: inexpensive), and often they utilize a small fuel efficient engine. Increasing the weight of this car by about 40% is not doing any favors to the already under powered car, and the fuel economy is going to suffer. Realistically, speed and acceleration are meaningless (of course the car will exceed the 3 mile per hour average human walking speed).

Improvements:
*Start with a different type of vehicle. Perhaps something that was designed to be large.
*Ignore the mad max spikes.

research tools:
http://www.hyundaiusa.com/elantra/specifications.aspx
http://www.hyundai-forums.com/197-i30-elantra-touring-forum/140546-load-capacity-2012-touring.html
http://en.wikipedia.org/wiki/Humvee
http://www.fisherplows.com/fe/showroom/homesteader
http://www.engineeringtoolbox.com/gauge-sheet-d_915.html
http://www.unc.edu/~rowlett/units/scales/sheetmetal.html