Krebs said she believes the market is thriving on potential buyers looking for a good deal.
"We often seen spikes in shopping when something is in the news," she said. "Some of that's just curiosity, checking out what the prices are, but there may well be people that are looking to see if people are selling [used Volkswagen diesels] for cheap."
The U.S. online market trends come as there are indications that diesel Volkswagen sales are declining in Europe. MeinAuto.de, a German online car dealer, saw a 10 percent slip in inquiries last week, according to Deutsche Bank analysts. Additionally, a U.K. price data firm, Glass, said that Volkswagen TDI valuations fell 0.2 percent in September.
It's still too early to tell if U.S. Volkswagen owners are using online marketplaces to unload their used vehicles. Krebs said AutoTrader has no data on any increase in listings just yet.
Despite the increases in shopping activity, Karl Brauer, a senior analyst at Kelley Blue Book, told CNBC that the site hasn't seen any substantial or worthy valuation shifts so far.
"I think we see the potential for some downward slippage of values but probably only along the lines of 3 to 5 percent," he said.