Could you use something along this line or possibly this?

They look a bit big, the pictures below show one fitted and one missing.  They are approx 9mm long by 1.5mm wide by 1.5mm deep.

Any luck? I need some also and can't find. 

@April77I'm afraid not, I still need one and so does my daughter for her Dell laptop.

Hello I have also had this problem but I have read about this in another article:

https://www.dell.com/community/Laptops-General-Read-Only/I-lost-the-rubber-bottoms-that-go-on-my-laptop-where-can-I-get/td-p/1066072

Stating that rubber bottoms are covered under warranty. 

Hi did you find anything? I have the same problem

Hi Rashmi, I'm afraid not.  It's almost like they dont exist!!

https://www.parts-people.com/index.php?action=item&id=6549

I think this is the part we are all looking for