A "sunroof hamster" is not a recognized term in professional contexts. However, if used colloquially, it could metaphorically refer to a hamster, or a person (non-gender specific) exhibiting excessive and eager behavior to provide fellatio while their partner lays on top of a the vehicle with their hamster bits exposed through the sunroof.
In casual conversation, "sunroof hamster" might be used metaphorically to describe someone eagerly seeking attention or affection.
I asked to spice things up so she offered a ‘sunroof hamster’… wow!!
When a man lays across the roof of a automobile and hangs his member from the sunroof,meanwhile the occupant(s) drink from said member like a hamster in a cage drinking from the bottle
Man, Carrie gave me a hamster sunroof in my 1500 last night it was crazy, esp doing 45 in a 25.
When a man lays on top of the roof of a car and sticks his dick through the (open) sunroof and the woman essentially acts like a thirsty hamster or vice versa when a woman splits over the sunroof and then man eats that up from inside the car
Mark: yeah bro my girl sent me this tiktok about the hamster sunroof and let me tell you dude, you can’t knock till you try it, best nut ever
James: damn man I wish my girl would eat my meat like that