Also probably worth adding a bit of information about front parking sensors as I couldnt find a lot of details about it when I did my swap. My car has them but the Black Edition OEM S4 grille I bought second hand didn't, so didn't have the sensor holes holes. I wasn't quite sure what I'd find or how easy it would be to mod the new grille to take the sensors securely, but it turns out its quite simple
Firstly, I was worried the clips that held the sensor into the grille might be moulded in to the back of the grille and I was envisaging bodging together a makeshift means of holding the sensors, but thankfully the holders are separate little stick-on clips that can be pulled off and stuck back on to the new grille with new double sided tape
Next job was making the holes in the new grille, and again handily Audi have the hole centres pre-marked in the back of the moulding so no guessing about position. You can just about see it here but I forgot to take a proper photo beforehand so apologies for the crap pic.
The hole needs to be exactly 18mm, which I drilled with a flat drill bit like this
Don't rely on the dril bit sizing though, the bit I bought was actually around 18.5mm when I measured it and a test hole drilled in some scrap plastic confirmed the hole was slightly too big so I just filed each edge down a little to make it the right size.
I then used a small ~3mm drill to make a pilot hole from the mark on the inside, then actually drilled with the flat drill bit from the outside inwards to get the hole as clean cut as possible on the visible outer face. I still had to tidy up a couple of slightly raised edges with a stanley knife but now you wouldn't know it wasn't OEM.
As the old grille central section was grey so were the sensors, but the new grille was black so I "wrapped" the sensors with a strip of good old black electrical tape which is just wide enough and more than good enough at least until I get hld of an offcut of proper vynil wrap! It's easy to do as the rubber surround just pulls off so you can wrap the sensor then put the rubber back on to keep the edges held down nicely.
Finished article:
Firstly, I was worried the clips that held the sensor into the grille might be moulded in to the back of the grille and I was envisaging bodging together a makeshift means of holding the sensors, but thankfully the holders are separate little stick-on clips that can be pulled off and stuck back on to the new grille with new double sided tape
Next job was making the holes in the new grille, and again handily Audi have the hole centres pre-marked in the back of the moulding so no guessing about position. You can just about see it here but I forgot to take a proper photo beforehand so apologies for the crap pic.
The hole needs to be exactly 18mm, which I drilled with a flat drill bit like this
Don't rely on the dril bit sizing though, the bit I bought was actually around 18.5mm when I measured it and a test hole drilled in some scrap plastic confirmed the hole was slightly too big so I just filed each edge down a little to make it the right size.
I then used a small ~3mm drill to make a pilot hole from the mark on the inside, then actually drilled with the flat drill bit from the outside inwards to get the hole as clean cut as possible on the visible outer face. I still had to tidy up a couple of slightly raised edges with a stanley knife but now you wouldn't know it wasn't OEM.
As the old grille central section was grey so were the sensors, but the new grille was black so I "wrapped" the sensors with a strip of good old black electrical tape which is just wide enough and more than good enough at least until I get hld of an offcut of proper vynil wrap! It's easy to do as the rubber surround just pulls off so you can wrap the sensor then put the rubber back on to keep the edges held down nicely.
Finished article: