What the heck is it??

[Buzz]

I hope you didn't pay a Superformance price. Normally we need more pictures of specific areas for a positive ID, but the small-diameter, extra wide roll bar hoop, the deep vertical lip around the engine compartment opening and the firewall "bumps" indicate that you probably have a B&B / LA Exotics (earlier brand name) replica. Live axle and very different car (price-wise and other factors) from an independent rear suspension Superformance replica. Be wary of the creative titling - that can lead to problems. Other than maybe some Mustang II components, highly unlikely there are any significant chassis sections that could qualify it to be titled as a Mustang.