Top 10 New Vehicles that Languish on Dealer Lots Published on January 16, 2017 in Top 10 by Michel Deslauriers Photo: Buick 3- Buick Regal (tie)This sporty Buick sedan hasn’t changed for a while now, and its sales have been slightly dropping in the past few years. General Motors has plenty of in-stock Regals though, good for 196 days, or six and a half months of sales.