*sigh*
*puts shoes on, gets garage keys, goes out door, locks door, open garage, find something to measure with, goes back outside garage, crawls under car, realises he cant see, goes back in garage, finds torch, goes back outside, goes back under car, realises batteries are dead, goes back in house to find batteries, steals batteries from telly remote, goes back outside, crawls under car, measures exhaust, goes back in garage, puts away measuring tool and torch, locks up garage, unlocks garage, takes remote for telly batteries out of torch, locks garage, unlocks house, shoes off, back on laptop to probably reveal its 2.25" anyway!*