Retro-Fitting front parking sensors

[quattrodlo]

Okay so i am about to have the RS4 grille fitted and the only number plate backing panel available for that grille comes with the 23mm holes ready for parking sensors.
I would consider retro-fitting the sensors but Audi do not do it. Any ideas?
Alternatively are there any other way of filling the holes and keep the nice appearence?

[warp_speed]

I think they can be retrofitted, think I seen a retrofit kit in kufatec http://www.kufatec.de/shop/product_info.php/info/p1106_c118_APS--Audi-Parking-System-Plus---Front-Retrofit---Audi-A4-B7-8E.html

[Two_Stripes]

I had an s line, now converted to rs4. I reused my original backing plate