Think it was mid 80's

started out as live action, a boy gets a large present, then goes into it and it turns into a cartoon world where he is driving a car.

all I can remember at the moment

anyone got any ideas?

The Phantom Tollbooth (70)
a.k.a. The Adventures of Milo in the Phantom Tollbooth

(Live action-part)
Milo is a typical brooding kid, bored with his life, until he gets an unexpected package. It's a small car and a magical tollbooth, that's the doorway to another world.

(Animated)
His otherworldly trip includes many life lessons he must learn to become a well rounded and more mature individual.
He meets several characters on the other side that are the living embodiments of puns. His faithful friend, Tock-(the watch dog that never allows him to forget that time is a precious resource), The Humbug-(A large,self-important bug with lots to say, but everything he has to say amounts to nothing). The WhetherMan-( A man who seems to be preoccupied with making decisions), The Spelling Bee...self explanatory, and several others.

He finds two kingdoms on the brink of chaos. The land of letters and the kingdom of numbers. Only the princesses of the two lands (Princess Rhyme and Princess Reason) can bring peace to the land, but they've gone missing. Milo and friends go out on a quest to find Rhyme and Reason and return them to their kingdoms.

------------------