Basically, it means "the buttocks," but that just makes it sound so common. It's basically means a pair off ass-cheeks that you just can't take your eyes off. Like when you're walking in the East Village of Manhattan behind a pair of tight-jeaned cheeks, be them falling out or not and you are mesmerized. That is a Parking Lot!
"Damn, bitch. Yo Parking Lot showin!" "Damn, she got a fine PARKING' LOT." "He backed that PARKING' LOT right up on me. He could tell I liked it." "I can feel it in my PARKIN' LOT! MY PARKIN' LOT! MY PARKIN' LOT!" That was from Madonna's Hearbeat. Insert it...."You can catch me poppin' like (I keep on dancing to the night)." Instead of "You can catch me poppin' like, it's, "I CAN FEEL IT MY PARKIN LOT." It works. Trust.