At around 40-55 mph the car will slip or learch.....It feels like the transmission is slipping or it looses power intermittently at this speed. It basically stalls out...the rpm gauge flutters a little when this happens...I normally goose it to try to get past that gear/stage but sometimes that makes it completly loose power for a few seconds. I have called my dealer twice and they claim its not a covered powertrain issue and I will have to pay for the fix. This car has only 42k...there should not be a transmission issue already - or if its the spark plugs like my husband says that is even worse at that low mileage.