The most common and most likely answer to this crossword clue is the 7 plus 7 letter word CHELSEA TRACTOR
I've seen this crossword clue in The Sunday Telegraph
C
H
E
L
S
E
A
T
R
A
C
T
O
R
More clues leading to the result CHELSEA TRACTOR
- Large vehicle has this accelerator modified — one gets going
- Charlotte races about in this?
- Suspect character stole so-called off-roader
- Charlotte races around in it
- Dodgy character stole vehicle in London
- Huge 4WD car, the real cost laughable?
- Dodgy character stole a 4×4?
- Character stole awfully large car
- Sadly, the last race in my 4×4?
- Cash wanting as monstrous car eats petrol — that’s taking the pee!
Buddy explains!
The straight part
We know that "large car" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case large car = chelsea tractor.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.