I was driving home the other day and there was a scraping noise I looked to see the plastic skid try, under tray thing under the engine had come loose and was dragging under my car i managed to get it back on, anyway I went through a puddle and it came back off, anyway my mate said they come off all the time and will keep doing it just take it off, my dad said the same I thought I'd ask here too should I just discard it or replace/fix it  

Best to keep it if you can, keeps the engine bay cleaner and drier.  Sounds like you may need some new fixings if it keeps falling off.

It's not essential so you can leave it off if you want.

Yeah I used the fixings that were already there and one was missing so I used a wheel liner fastener form a bmw to fix it and worked a treat, it looks like its sagging in the middle, is there a fixing there or is it the 3 at the front and 2 at the back 

Go over ramps much slower, this if the major cause of them being knocked loose.

I went down to see if there was anything I could do, seems to be held on ok, I'll try be more careful 

12 hours ago, casuk said:

I'll try be more careful 

Not so long ago I saw a pretty new Corsa go over a squared ramp at speed, infact it never slowed down! As the car launched itself upwards and nose dived, the front end clobbered the floor and the black plastic edge got partially torn off and went under the front wheel, then the front wheel ragged half of it off and spat the part behind the car, driver just kept going and wasn't aware they'd damaged their car, I picked up the plastic part and left it by the kerbside.

Think I'll go up the scrappy and see if I can pick one up, it's just sagging in the middle as if it's been bent and wont go back into shape, not flat like I'd expect it to be, looks like there is a fastener that should be in the middle to hold it up aswel as the fasteners front and back