It might not be all that hard- take the Challenger floor, adapt 300 quarter panels and C-pillar, roof to shorten, put 300 front clip on, and design new door skins.
I'm sure that there are other complications that I'm not thinking of, but it would be awesome if they'd offer such a car domestically too...
I'm sure that there are other complications that I'm not thinking of, but it would be awesome if they'd offer such a car domestically too...