I realize that I am late to the discussion- but I just got my Greenlight Bluesmobile diecast today.
There's quite a bit that can be done to make it more realistic... but the thing that jumped out at me immediately were the WAY undersized license plates. This will not do I said to myself. So I found a company that sells 1:1 reproductions of the license plates used on the Bluesmobile and captured a high res pic from their website.
I pasted the photo into a document, resized it to .25" H by .50" L and printed it out on my Canon color laser printer on heavy stock light gray paper (photo paper might be better but I wanted to go for a weathered look). I carefully cut out the images with a sharp scissor, being sure to round off the corners. I attached them to the scale Bluesmobile's bumpers (the rear plate attached with a slight off center look- as seen in the "I Hate Illinois Nazis" scene) with clear contact cement and here is the result:
I think that looks better and I hope that you do too.
- Detail the backup lights (very obvious in several scenes).
- Handles in the interior for the spotlight.
- Possible weathering and 'junk' in the interior such as sunglasses, pack of cigarettes, 8-track player with "The Best of Sam and Dave" tape, etc. (if I can get to it)
- Interior rear view mirror (again; obvious in some scenes)
- Replacing the rear window. Yes I know at one point in the movie the car has the rear window shot out- just my preference.
- Rust near the passenger side front door handle.