Parking at Osaka Bay Area

Hi,

I'm travelling with a rental car, hence need more information on parking spaces in Osaka Bay Area. Among the plans are to visit the Kaiyuukan and Legoland Discovery Center etc. Is there any nearby parking spaces available and how much should I expect the parking fee will be? Or is there any free parking spaces nearby.

Thanks.

Very limited spots

Very expensive costs

All viewable on Google maps