Took my '00 S2000 with 94,000 miles into Costco for a tire balance. First time it had been up on a lift in over a year. The moment I drove it away from the shop I noticed a humming noise and figured it was the wheels. Got home, about 20 miles away. Shortly thereafter I took it to a shop around the corner who lifted it and said the drain bold on the diff was only finger tight and had leaked all but a teaspoon of its lubricant.