The most common and most likely answer to this crossword clue is the 7 plus 4 letter word EJECTOR SEAT
I've seen this crossword clue in The Guardian
E
J
E
C
T
O
R
S
E
A
T
Buddy explains!
The straight part
We know that "See to car and jet crash — with this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case see to car and jet crash — with this = ejector seat.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.