Bad jumpstart


Go Kart Champion
I made the mistake of letting a friend hook up the jumper cables to his car. I assumed he could handle red to red and black to black but apperently not. I jumped the car with the cables on backwards, and instantly the horn of my gti began to blare and the headlight washers shot out and began to spray fluid. We jumped it the right way after that but it couldn’t run on it’s own without giving it throttle. I drove it around the parking lot and it ran fine but then it beeped and the check engine light, along with the epc light and the traction control light came on. I left it as is because I feared I’d mess it up more. I should also note radio lights and radio itself quit working. Any thoughts? 2006 gti 2.0L
Any updates on what you have found. Hopefully just a battery.