What a money-grubbing PCN !! Disgusting really but difficult to counter. London councils are venal and rapacious, so if you submit reps will send you a Fob-Off letter. You then must decide whether to take them to London Tribunals. Unless the PCN contains fatal errors this would have to be on a de minimis basis, (offence too trivial for enforcement). However it would depend on what adjudicator you got "on the day", as some won't countenance 10 thousandths of a inch inside a bus stop as de minimis. More shame them.
The main point here is that it isn't where your wheels are, it's where the car/vehicle is. Other OPs on here have been walloped for intruding into yellow lines and saying their wheels weren't on the lines. But their vehicle was within the lines. However see what the others say.