Can you plug in a regular genesis 16-bit cartridge into a 32X for better performance or graphics? I'm seeing people on YouTube play Genesis games on the 32X but I'm not sure if their ports. In other words if I buy a 32X and install it, will I have to unplug it to play genesis games?
According to the original 32X manual, it seems like you can directly plug in Genesis games to the 32X and they will work, with the exception of Virtua Racing.
On page 6:
To play conventional Genesis 16-bit cartridge games, just insert the cartridge into the cartridge slot on the Genesis 32X. Before playing the 16-bit Virtua Racing game, remove the Genesis 32X from the Genesis unit.
As far as why Virtua Racing doesn't work with the 32X, it seems to be related to the Sega Virtua Processor chip that was built in to the game cartridge. Virtua Racing also doesn't work with the Genesis 3 (without modifications) for the same reason.
Additional information : The 32x displays the video a bit better. The model 1 Sega Genesis consoles can be prone to "rainbow banding" and the video encoder in the 32X provides better image quality.