I put my front plate in the windshield when I park and they let me slide.
As for the $10 vs $38. If you put the plate on and go to the station and show them, they will stamp the ticket and then you owe $10. Otherwise, just pay $38.
Where was the car parked? If you park in a private lot, then you shouldn't get a ticket. City lot or on the street they'll get you.
2011 E93 - Space Gray - 6MT/Silver Novillo/
OE Tuning/Gruppe M Intake/ACS Springs/Vorsteiner CF Type I Rear Diffuser/Textured Matte Black Custom Powdercoated OEM 359s/Painted Reflectors/Matte Grille, Hood Vents and Side Markers/Arqray Race Exhaust/MS Pulley