Previously i have always left Thailand by Air before my 90 day allowance expires.

Looks like i will need to make my first border crossing to get a fresh 90 day stamp, would be using Chong Mek.

Just checking if this border crossing is open 7 days ?, is there some whare i can park my vehicle at the Thai side that is close to the crossing point ?

Chong Mek like other border crossings is open every day they do not close for weekends or holidays.

You will be able to find parking just before the crossing.