I found the same thing happen during the cold winter months, but it seemed to be an intermittent occurance. However I just had my 07 ES 350 in the other day on a recall for a defective oil cooler hose as well as an oil change. I asked the dealer to check for any oil leaking under the can and they could not find anything. Hopefully the oil line replacement will do the trick. Another possibility is the dealer may have spilled some oil while filling it or they may have not tightened the oil filter housing causing it to leak. My advice is contact the dealer again and explain what is happening to your car. Hopefully this helps you and good lick.