DETROIT – Volkswagen's efforts to do right by owners who unknowingly purchased cars and SUVs that cheat on emissions tests have run into some speed bumps. Owners say the company isn't delivering on a promise to quickly buy back their vehicles. Some complain about multiple requests for paperwork, even after being told their application was complete. The German automaker acknowledges some hiccups, but blames delays on an overwhelming volume of buyback requests. A company lawyer told the judge handling the VW case that almost 400,000 owners had applied to have their vehicles repurchased in the three months since a legal settlement was approved. "I almost feel like there's a stall tactic going," says Eric Larson, 42, a software salesman from suburban Minneapolis who has spent three months trying to get VW to buy back a black 2012 A3 made by VW's Audi luxury brand. "That's what scares me about this thing."