I'm with those that say leave the filler door where it is, for the same reasons. Not everyone goes to Costco, but I'll say that having the doors on the passengers side makes my wait longer every time.
I'd like to see some more development in the handling department. Dare I say something like a Track Pack and such.
I like the idea of having a little more light in the interior too. Obviously finishing the ABL would be cool.
More unique colors. I love some of the greys and blacks that I've seen on some Dodges and imports; ones with a lot of metallics. I like most of the available colors now, but more couldn't hurt.
Some more accessories. It'd be nice to see more support, in the way of performance, much like another one of the Big Three does.
Another vote for higher quality interior materials - leather, etc.
I'd also like to close with thanking those who will be trying to present these suggestions and comments. It's great to have a sense that the company does care about the customer and what they like.
PS - Z28