Clue: Toilet's out of order, blocked by model's 17 across (8)
Answer: STILETTO
Explanation: Toilet's out of order, blocked by model's 17 across (8)
An envelope ('blocked by') of T (Ford 'model'; which T is your choice) in ~~SILEOTT~~ SILETTO or whatever, an anagram ('out of order') of 'toilets'.