The most common and most likely answer to this crossword clue is the 10 letter word DORMOBILES
I've seen this crossword clue in Independent
D
O
R
M
O
B
I
L
E
S
Buddy explains!
The straight part
We know that "Customised bedrooms touring Illinois?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case customised bedrooms touring illinois? = dormobiles.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 DORMOBILES mean?
DORMOBILES noun- A campervan.