Hi billie,
I have also just joined the forum few months back and have been talking alot. :P
As beachbum said, I also started modelling young age, and only start to realize I could paint the model when..... well... after building like 10 or so grey plastic finish model planes (those days I could get hasegawa planes in Parksons with ang pao money).
I started like .... well... 8 years old i think, and stop the hobby when I was 18. When I go to Australia, I found huge Modelling Supermarkets and they sell Modeling Magazine at newspaper stalls. I kept myself updated in the hobby until I got back to the hobby couple of years back.... I still have stash of stuffs I bought from Australia.... mainly update sets.
Coming back to you diorama, I suggest you first start with reference photos of downed planes..... ME109... you mean BF109?
Some image search of shot-downed bf109:

This image shows some bullet holes near the cockpit. However, it crashed with soft landing on wide grass land, so..... not realistic to depict "blocking road crash". If wide land... how to block the road?

Wanna build some engines?? ^_^ ^_^

Found this excellent photo on the web. But might be difficult for you to make the realistically thin body material in 72nd scale. But this one really works for you.

Another good photo, note the bent rotors and twisted metals.
The rest... find youself.
It'll be good if you can show some recovery vehicle trying to tow away the downed BF109.... and probably the tank commander is debating whether or not to just ram over the plane with the Tiger..... Just some brainstorming... :D