Why do Shelby cars look like ford cars?

Shelby cars look like Ford cars because Shelby American, the company that produces Shelby-branded vehicles, heavily modifies Ford Mustangs and other Ford platforms. They don't design their own chassis or body from scratch. Instead, they take existing Ford models and add performance upgrades, styling enhancements (like unique body kits, spoilers, and badging), and interior modifications to create their high-performance versions. The underlying structure and basic design remain fundamentally Ford.