My wife and I were at a stop light behind a box truck in our 2018 Jeep Wrangler, about 15 feet between us. I had slowed to stop and had my foot on the brake. All of the sudden the Jeep reved up (idle increase), did not see the tachometer, and with my foot on the brake accelerated into the box truck in front of us. When it started to accelerate, I pushed the brake peddle to the floor to stop the Jeep but it did not do a thing. I see 2 problems her: 1. The acceleration when stopped 2. The brake did not hold. There were no injuries or damage to the box truck. We were able to drive the Jeep about 20 miles to the dealer we bought at. It is ow being worked on in the body shop. The Jeep dealer technicians did a computer check on any codes that were activated, but unfortunately all after the fact.