While Knueppel and Andy Hyer, a spokesman from Hyundai Rotem, the company that built the cars, stood side by side at a media conference Wednesday, and Knueppel noted how helpful the company has been, there were clearly unresolved tensions between the rail authority and the company. They were both reluctant to go into detail over how the original beams failed, and why the faulty weld designs were used. Another potential sore spot is who's going to pay for this. Hyer said his company would cover the costs of parts and repairs, though he wouldn't put a dollar amount to it. Knueppel, though, laid out what the car shortage was costing SEPTA. $235,000 in refunds paid in July alone. Up to $1 million a month by Labor Day for leased rail cars. A 10 to 20 percent drop in ridership. It remains an open question how — or if — Hyundai Rotem will cover the indirect costs of the vehicle failures. Knueppel and Hyer acknowledged it could be a contentious question to answer.