Why do we say "go by car" and not "go with car"?

[Keniaboy]

English Grammar Tests, Elementary Level

ESL/EFL Test #106 "Beginner Grammar Questions Test (1)", question 2

Every morning, I go to work ......... car.

(a) for
(b) by
(c) in

English Grammar Tests, Elementary Level

ESL/EFL Test #106 "Beginner Grammar Questions Test (1)", answer 2

Every morning, I go to work by car.

Correct answer: (b) by

Your answer was: correct
_________________________

my answer is correct, but why by?

Keniaboy

[Mister Micawber]

.
It is idiomatic: modes of transportation, when unmodified, take the preposition 'by'-- by car, by taxi, by train, by plane, but in a sports car, in my car.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber