The fifth graffiti can you find during the repair of the truck in the junkyard. On the right side of the engine compartment is a Fuel Filter. Check this filter and Chloe put this filter aside, interact again with the fuel filter and Chloe create a spot for a graffiti inside the bonnet.
For a visual guide open the spoiler, inside you find my video with all 10 graffiti locations.
*** Spoiler - click to reveal ***00:08 - Optional Graffiti #1 (American Graffiti)
00:43 - Optional Graffiti #2 (Extra Credit)
01:16 - Optional Graffiti #3 (Peer Review)
02:05 - Optional Graffiti #4 (Monthly Masterpiece)
02:53 - Optional Graffiti #5 (Spit Take)
04:38 - Optional Graffiti #7 (Hello Nurse)
05:26 - Optional Graffiti #6 (Venting Machine)
06:53 - Optional Graffiti #8 (A Penned Appendage)
07:57 - Optional Graffiti #9 (Drunk Drawer)
08:41 - Optional Graffiti #10 (Messed Up)