I have no clue why someone would do something like this. It doesn't sound like a good idea to begin with. I weld probably 8-9 times a day at work.. and I know from experience that regardless of how well you can weld, the weld is still the weak spot.
Put glue on a piece of paper.. stick another sheet on top of it and let it dry. When you pull it off it will tare at the glued section. Now super glue 2 pieces of plastic together... and do the same thing... Guess what!? It will break in the same spot. He at least could have tried to DR it up a little and reinforce it with another piece of metal. Or a thicker weld.
As it sits now.. over time the car will bow in the middle. The doors will not line up in a few months. And if he has a fender bender the car will be totaled. Weld in a roll cage. It might help the car. It will save your life if you have a 30+mph wreck.

I selected yes because I want to follow this car till the end. It's entertaining to watch people test things, just to find out that they failed.

And as for the Tech student.. you are correct about "If the weld if correct, it will be stronger than the metal." But there is a small issue with it.. IT WILL STILL BE THE WEAKEST SPOT IN THE METAL. You can melt the metal perfect and create a perfect weld, but it will still fold before the solid metal. You can't recreate the same composition of strength of 1 whole piece of metal with a cut then a weld. Unless you have the magic UNDO welder.. that erases the cut to begin with. You do have a valid point though, just get some more experience with welding.

But I will give reps for doing something productive with a car.. even though it's for a silly cause.