Plaster pieces, lots of plaster pieces
Step 1 : Build a large grid of plaster wall floor pieces colored to your preference of road material. You can expect this to be in the several hundreds and get bored very quickly of placing these. I use the gray asphalt path as default so I can match the road with the path using colour code #999292.
Step 2 : plan out your parking spaces layout and place the safari jeep vehicle (African off road vehicle), using vertical plaster pieces or primitive rectangles, make a parking space to your standards around the vehicle. You can then duplicate the parking space to make a line of spaces, duplicate more and more and eventually you get an empty parking lot.
Step 3 : you can add lights, foliage planters, kerbs to decorate the parking lot both inside and around it. Optionally you can place the jeep to fill the parking lot,
do not use workshop vehicles to fill up the spaces, as nice as they look they are like 800 pieces per vehicle. The average realistic parking lot is 200-400 spaces big.
Or you can just watch my Calgary zoo entrance speedbuild showing how to build a small parking lot, here i used the path method instead of the plaster floors. Sadly I never recorded my detailed Houston zoo one with realistic road texture work :
Source: https://youtu.be/iXz4SE86Tjk?si=USyJqFLS3wfh9aKM