Introduction:
After seeing a 205 GTi with a de-badged (badgeless) grill I thought I'd make one since you can't buy them at the moment like you can, say a Gutmann-style one. Its also weird how much different the car looks from just removing the badge.
The job:
Removing the badge is easy, its filling in the space it leaves with "bars" that is the hard part. So the first thing I did was to get another standard 205 grill and use my old one as a "donor" to cut up. The badge comes off by unclipping the pins behind the grill. The black frame behind the bars also comes off in the same way but I left this on as I seemed to destroy the clips trying to get them off and I didn't want to damage/crack the new set of filled bars whilst clipping it back together. As I was going to paint the grill, I masked the black plastic parts up.
I cut three sections of bar from the other grill, just slightly longer than they needed to be to fill the space the badge has left, because after all you can always file them down but you cant stretch them if they're too short! I cheated and used a bench grinder to quicky file down the bars so they were a perfect fit for the spaces. I now needed to bond the 3 bars onto the second grill. I used arraldite which when mixed and used properly sets rock hard (so it can be sanded) and bonds very well.
additional parts bonded in the grill (pic by PUG-205-XS)
As it was setting I tried to keep the bars in place but it turned out that only the top bar was a reasonable fit (and even that was a bit sunken). I also only now notice that the middle bar is for some reason thinner than the rest of the grill and looks totally out of place. Don't know why it was so thin, maybe it had sunk or something. So at this point I was thinking of starting again since I didn't want to do loads of filling... but I kept going!
grill sprayed with primer and ready for painting (pic by PUG-205-XS)
I used a plastic filler primer which is very thick; basically you can paint as much on as you like and it doesn't run it just builds up. So a few thick coats of this and wetndry in between and it started to take shape but the middle bar still looked way off. I was tempted to leave is like this just to see what it looked like on the car but decided to use bodyfiller on the middle bar; a little skim was needed.
grill, by now sprayed with red paint (pic by PUG-205-XS)
I mixed it but missed the 50:1 filler:hardener ratio and put in something like 10:1, so it started setting as I was putting it on which turned it all lumpy and wouldn't spread - basically it was going to be a nightmare to sand. And I was right! - until I found I could get a grinder on the case if I was carefull. 10 seconds later I ground it nice and flat and the grill was only a few coats of primer & light sanding off painting top coat.
background bits painted black (pic by PUG-205-XS)
I used 800grade wetndry to finally smooth the whole grill before the top coat. As there is a square section where the badge used to sit I decided to paint this bit black first so it wouldn't be so noticeable, and then mask it up before the top coat.
grill fully re-assembled and ready to go back onto the car (pic by PUG-205-XS)
I masked it up and painted the top coat but I put so much paint on it covered the masking tape. When I removed the tape it peeled the paint a bit 
. Not too much though; I've cover the rough painted edge with black tape.
Summary:
The reason I've put so much of where I went wrong is to give an idea of how bad it can go and what I did to change it and how if you carry on you can turn it round into the masterpiece you see below:
the car looks much different...
...and the job looks very professional too 
Well it looks OK to me! The only problems with it now are the middle section where the badge used to sit is basically a big flat square and this can be seen through the bars but its not too bad from distance. Also the paint needs flattening but that can be done later. Basically if you cut three pieces of bar from a spare grill and stick them on reasonably straight it'll look OK!