Yes, there are several parking areas both within Makkah and outside the city. However, these parking areas are usually utilized during Ramadhan or Hajj. My suggestion is that you follow the sign boards which will lead you to the Haram. Just three or four kilometers before you reach the Haram, look for a good parking space either in front of some important supermarket or some hotel. Get the name of the street where you have parked your vehicle or ask the shopkeepers for any special landmark. Lock your car and proceed to Haram. The average cost of the taxi would be just around 10 Riyals to the Haram. Make a note of the place where you have parked your car lest you forget and also make sure the car is parked in a parking zone. Alternatively, you can get hold of a taxi after entering Makkah and ask him to help you locate a parking place near the Haram. He will guide you and will charge you around the same amount as stated above. The taxi driver may also help you find a good hotel at reasonable rates near the Haram. That is what I used to do whenever I went to Makkah by road.