crash hot

Etymology
Perhaps a nonstandard adverbial usage of +.

Adjective

 * 1)  Very good, excellent; very well.
 * Well well well, don′t you look crash hot in your new sunnies!
 * I'm sorry boss, I can′t come in to work today, I′m not feeling too crash hot.

Usage notes
Apparently most often used in the negative as a form of sarcasm, e.g. "That doesn't smell crash hot, does it?!"