I think it looks a bit to conservative. I like the CRG Banner: I would have the CRG banner with red back round large and centered across the front of the shirt, have the website either under it or on the back by the neckline and then some eye catching emblem(s) on the back: either RS Z/28 SS *or have the CAMARO chrome emblem with your one liner under it.
Now if things went well and you wanted to develop a polo shirt, then I agree with Sauron327 that you keep it small. Polo shirts are more business oriented and have a small logo on the front.
My friend gave me a GOLDEN GATE MUSCLE CARS (car club) shirt and it is black with the golden gate bridge across the center with there logo in the middle, I think a t shirt lends itself to more artwork.
If you are just going to create a small logo, why not just hire a vendor to make a CRG patch, then guys can purchase them and put them on T-shirt or POLO, or hat of their liking
which ever color they want.