Looking on the internet deeply has found these results:

on a taxi is the most popular phrase on the web.

In a taxi 131,200,000 results on the web	on a taxi 131,300,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
In a taxi, halfway between home and the hospital. In a taxi you can do anything, but in your home, nothing! He's just left in a taxi. You came in a taxi with a nurse. Just you and me in a taxi like regular folks. White people, in a taxi. Yes, I'm really in a taxi. My brother's outside in a taxi.	Politician in Chicago, killed in broad daylight on a water taxi. The Taxicab Act requires all persons seeking to operate a taxi or carry on a taxi business to apply for and obtain a taxicab business licence from the Taxicab Board. bound people with disabilities: services of this type are not yet widely available in Rome. Listen, mate, could you, could you put a GPS trace on a taxi for me, please? You can always splash out on a taxi, or... whatever. At present the association is seeking to implement a project centring on a taxi service for wheelchair Skipping out on a taxi. A Palestinian man emerged from a taxi on a busy shopping street in downtown Jerusalem with a machine gun in his hands and hate in his eyes.

In a taxi

131,200,000 results on the web

on a taxi

131,300,000 results on the web

More popular!

Politician in Chicago, killed in broad daylight on a water taxi.
The Taxicab Act requires all persons seeking to operate a taxi or carry on a taxi business to apply for and obtain a taxicab business licence from the Taxicab Board.
bound people with disabilities: services of this type are not yet widely available in Rome.
Listen, mate, could you, could you put a GPS trace on a taxi for me, please?
You can always splash out on a taxi, or... whatever.
At present the association is seeking to implement a project centring on a taxi service for wheelchair
Skipping out on a taxi.
A Palestinian man emerged from a taxi on a busy shopping street in downtown Jerusalem with a machine gun in his hands and hate in his eyes.