Welcome Polaris to Grassoâs Garage! Known for their off-road excellence and long-lasting success in the powersports industry, Polaris wants a slice of the Grassoâs Garage open-air review pie. In Grassoâs Garage this week, itâs the Polaris Slingshot Signature LE. Their top-of-the-line three wheel recreation vehicle certainly brings out superior style to show off, while enjoying the comfort, .