He died and left behind a wife, his parents, a son and daughter

If a man dies and leaves behind a wife, a son and a daughter, and a mother and a father, the estate is to be divided as follows: 

The wife gets one eighth, because Allah says (interpretation of the meaning): “but if you leave a child, they [wives] get an eighth of that which you leave”

[al-Nisa’ 4:12]. 

The father gets one sixth and the mother gets one sixth, because Allah says (interpretation of the meaning):

“For parents, a sixth share of inheritance to each if the deceased left children”

[an-Nisa’ 4:11]. 

The rest goes to the son and daughter, with the male getting a share equal to that of two females, because Allah says (interpretation of the meaning):

“Allah commands you as regards your children’s (inheritance); to the male, a portion equal to that of two females”

[an-Nisa’ 4:11]. 

To divide the estate among the heirs, it must be divided into twenty-four equal shares of which

the mother gets four

the father gets four

the wife gets three.

The remaining thirteen shares go to the son and daughter, with the son getting double what the daughter gets. 

The heirs can agree to sell the house and car and divide the money amongst themselves, or they can keep them to rent out and share the income amongst themselves. 

And Allah knows best.