Dumb question about my underbody shield

2011 Nismo#91

The only need to take off 4 bolts and bend the plastic back to change the oil and filter, no need to remove any parts or push pins.

You don't need an aluminium one unless your original one is damaged or lost. There is no functional benefit to one over the other. And the aluminium is much cheaper then a replacement new plastic OEM one not to mention nicer looking when your under the car

Heres a link to the parts.
http://www.nissanpartszone.com/diagr...nt-747a004.png
http://www.nissanpartszone.com/compo...747-301_5.html