So close but so far!

I am really hoping that this weekend, I will be able to complete "A Perfect Nest for Mrs Mallard" but the last illustration is proving a devil. The school caretaker provides Mrs Mallard and her ducklings with an escort safely across the carpark and to the lake. I decide against a portrait of the caretaker (sorry, Terry - I know you were looking forward to your 15 minutes of fame), as scale-wise it would have made Mrs Mallard and her babies too tiny. So, I have them marching across the page in front of a halted car. This causes a further problem, as I don't want to show a real number plate and can't think of a good fictional one. I've tried masking the plate with the legs of watching schoolgirls (rather manga style) or having the truncated legs of the caretaker walking past but as yet, nothing is pleasing me. Think I need to give it a rest for today and come back to it refreshed tomorrow (although I've tried the same tactic for the past 3 nights and still no breakthrough!)