Top 10 New Vehicles that Languish on Dealer Lots, Fall 2017 Published on September 28, 2017 in Top 10 by Michel Deslauriers Photo: General Motors 8- Buick CascadaStill not available on the Canadian market, Buick’s little convertible climbs up two ranks compared to the January 2017 list with an inventory of 171 days. Buick announced mild changes to the car for the 2018 model year, so the 2017 edition could be interesting if it’s bundled with generous rebates.