No zakaah is due on rental cars and delivery trucks

There is no zakaah on rental cars or delivery trucks, rather
zakaah is due on the rental income if they reach the nisaab and one year has
passed. 

Shaykh Ibn Baaz (may Allaah have mercy on him) was asked: Is
there any zakaah on commercial trucks that go and bring grain etc, or camels
that are used for the same purpose? 

He replied: There is no zakaah on trucks and camels that are
used to move grains, goods and other things, because they are not prepared
for sale, rather they are prepared to be used to move things. But if the
trucks – or other things such as camels, donkeys, mules or other animals
that it is permitted to sell – are prepared for sale, then zakaah becomes
due on them, because in that case they have become trade goods and zakaah is
due on them, because of the report narrated by Abu Dawood and others from
Samurah ibn Jundub who said: The Prophet (peace and blessings of Allaah
be upon him) used to enjoin us to give zakaah on that which we had prepared
for sale. This is the view of the majority of scholars. Imam Abu Bakr ibn
al-Mundhir (may Allaah have mercy on him) narrated that there was consensus
among the scholars on this point. End quote. 

Majmoo’ Fataawa Ibn Baaz,
14/181 

The scholars of the
Standing Committee were asked: How should we pay zakaah on delivery trucks
and rental cars? Should it be based on their value or on the earnings? 

They replied: So long as
these vehicles are prepared for rental, then zakaah is due on the earnings
when one year has passed, not on their value. End quote. 

Majmoo’ Fataawa al-Lajnah al-Daa’imah,
9/349.