John Mayer and Jeff Ross Pick Up Bob Saget's Car From Airport

John Mayer and Jeff Ross's trek through L.A. traffic to pickup Bob Saget's car got one of them a keepsake of their dearly departed friend. And, no ... we don't mean Bob's car.

The singer and comedian shared what was clearly a pretty emotional mission for them ... going to LAX to pick up the Prius Bob had left parked at the airport when he flew out of town.

In the video, they reveal how much they had to pay to get the car out of the parking structure -- it wasn't cheap -- but Jeff stepped up to cover the tab, and John explained it was all about getting the receipt.

Jeff admitted he wants to hold onto it as a memory of Bob. John went even deeper, saying it's a way to keep his hand on Bob's shoulder, now that they'll never see each other again.

TMZ broke the story ... Bob was found dead in an Orlando hotel room Sunday, apparently dying in his sleep without suffering.

His good friends are clearly still shaken by the loss, but Jeff did have a few jokes during the car ride to lighten the mood -- he is the Roastmaster, after all.