The Yokohama IC uses the Minato Mirai underground public parking garage. If you happen to come by car, be sure to pay the 1500 JPY (about $14) per night parking fee to the IC and get the parking voucher(s). Otherwise, the parking fee will lighten your wallet to the tune of 12,480 JPY (about $120) per 24 hours.
When I first drove out of this parking garage after a 2-night stay, I was more than a little surprised to see the fare on the exit gate meter. But it sure was a great feeling to see that number drop to zero in large increments as I fed in the IC vouchers.