97 z28 6speed.
I was driving home tonight from class and I felt the itch so while at a stop sign, I gave it the heavy foot, and spun through 4th, when it finally caught in 4th and I shifted to 5th gear, Interior light flashed on.. I was like ok, is the car just flipping the lights on to still see if im inside the car? WTF? So Im just curious if this has ever happened to anyone, not a big issue but it did distract me for like a 1/4 of a second, which isnt a good thing when your playing at night.

 

I would check your rear hatch to make sure it is latched properly. This has happened to me before.

Rear hatch not latched, go over bump, hatch comes off of pressure switch turning on the lights, then it settles back down onto the switch turning the lights back off.

 

As stated above your rear hatch isn't latched. There's enough air force when driving to keep the hatch down even though it's not latched and the interior light stays off.