The most common and most likely answer to this crossword clue is the 6 letter word SOUPED
S
O
U
P
E
D
Buddy explains!
The straight part
We know that "car to go faster, if this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case car to go faster, if this = souped.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.
What does SOUPED mean?
SOUPED verb- To feed: to provide with soup or a meal.
- To develop (film) in a (chemical) developing solution.
- Alternative form of sup
- To sup or swallow.
- To breathe out; to draw out.
- To sweep.
- (Rhode Island, Massachusetts, Connecticut) Excited.
- In trouble or in difficulty. (Compare in the soup.)