Koenigsegg backs out of deal to buy Saab

Swedish exotic-car maker Koenigsegg Group has canceled plans to buy Saab from General Motors. GM announced that the deal was off on Tuesday and gave no reason why the deal fell apart, nor did the automaker say what would happen to Saab. In a statement, GM CEO Fritz Henderson said: "We're obviously very disappointed with the decision to pull out of the Saab purchase.

Mazda brings diesel back to Indy with 6 Skyactiv-D

Diesel has enjoyed great success lately as a racing fuel, but there's one place it hasn't appeared for more than six decades: Indianapolis Motor Speedway. Mazda's breaking that dry spell this weekend, when its Mazda 6 Skyactiv-D race car will head to Indy for the Grand-Am race. We like the 6 in both road trim and racing livery, but that previous diesel-powered racer -- the Cummins Diesel Special -- is pretty neat too.

Mercedes S-Class Coupe concept to debut at Frankfurt Motor Show

The new S-Class train rolls on sans abatement. According to Germany's Auto Motor und Sport, an S Coupe concept will go on display at this year's Frankfurt show. Expect the concept to differ from the production model in flashy trimmings only; the guts of the production beast will be there.