These are for 8mm holes, but are versatile to use in some that are wider. Some Subaru will have 8, some will have 10mm. 8mm are more common, but you need to verify the panel you are installing on before purchasing. 8mm is close to 5/16"
Splash Shield Clip/Retainer
Fender Liner Retainer - Advance Auto Parts
Infiniti Q50 Performance Parts
NISSAN 350Z
20 Plastic Push Clips for Fender Liners, Splash Shields, Various
20 Plastic Push Clips for Fender Liners, Splash Shields, Various Panels (20PushClips)
INFINITI FX35 & FX45 Exterior
01-20 GM Fender Wheel Well Liner Splash Shield Trim Push Retainer
20 Plastic Push Clips for Fender Liners, Splash Shields, Various Panels (20PushClips)
Infiniti G37 Aluminum Splash Shield