how to prevent the under tray
 

If I run TRF502X outdoors, how to prevent the under tray from being scarred by holystones?

You know that the under tray is not cheap. That is why I ask the question.

cheers

It's indeed not cheap, but considering the price of the carbon lower plate and how annoying damaged screws can be, I think the undertray it the protective cover - though not cheap, perhaps it's not that useful to protect it.

However, If you really want to protect it, you could add (glue, tape, whatever) another sheet of plastic underneith your undertray, or you could buy vinyl sheets that are also cut out as scratch protecting sheets for some cars...

Another option would be to buy a second hand undertray and use what's life is left in it, and keep the other one looking neat.

Use the cheaper B44.1 undertray.
Fits way better than the original one!!!!

I get a3 sheets of 0.5mm polycarbonate of eBay for £4 and make my own. Make up a wooden template of your undertray, sit the sheet ontop stick it in the oven on 150 degrees C and after bout 10 mins the sides start to fold around the wood. Once done run, quickly put it under tap and it stops shrinkage. Then just cut away the excess. Finish isn't as good as thermoforming I know, but I've got a db01 and nobody makes undertray for them. It's nicely sealed all round now and chassis is still like new. Hope this helps