You can buy a broken Mazdaspeed 3 for $3k and rebuild the engine for about $5k. asssuming you do all the labor yourself, you can get 350 to 400HP to the wheels in fairly practical car that gets 20-30MPG. Plan on $3k a year in maintenance, though, just in case.
Current Primary PC:
AMD 5800X | MSI X570 Carbon | G.Skill 32GB DDR4-3600 16-19-19-39 | MSI GamerZ RTX 3070 | ADATA 8200 Pro 1TB NVME | Micron 1100 2TB SSD | Crucial MX500 2TB | Seasonic Gold 750 Watt | Fractal Define S Case w/Tempered Glass | Noctua NH-D15 CPU Cooler | Sound Blaster Z | Noctua 4x 140mm, 1x 120mm Chromax | Pixio PX7 & PX275H Monitors