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!!