Tested again in Moodle 2.5.2+ (Build: 20131004), viewed in firefox
=>generate a question via the cq4m generator (OR us the included xml), import and publish in a quiz, open the quiz as student, look at the source code of the page and you will find:
<h1>New tires:</h1><!--155309103241127238253879523393781252781212523433338039-->A truck was fitted with 15 new tires.<br>These tires were selected from a batch which afterwards proved that 18% of the tires did not comply with the quality standards. The bad tires must be replaced. <p> <b>Determine the chance that more than 2 but less than 10 tires must be replaced, accurate to 4 decimal places.
The values of all the wildcards are plainly visible, so is the right answer but that value is obfuscated in a set of numbers between the comment tags.
This was presented during mrc2013. David Mudrak suggested to post on the tracker the question for a new wildcard type in which one could hide the right answer (generated outside Moodle) to get rid of the need to camouflage the right answer.
Not sure why you don't see this?
And yes Tim, excel can generate HTML like that