As self tappers were not going to be the way forward into securing the spoiler and it was too late to bond any nuts on the backside of the spoiler (No access) I bought some Rubnuts. These are essentially rivnuts that just push in and secure when tightened by flexing and trapping the fibreglass between it.
I bought m4 rubnuts and carefully drilled out the holes in the spoiler to 7.5mm. The OD was 8mm on the nuts so they took a little twisting/pushing to fit in but I wanted them to be relatively tight to stop them spinning when tightening the bolts within.
20180619_194938 by
Louis Walker, on Flickr
20180619_195016 by
Louis Walker, on Flickr
Bought some 25mm m4 washers to spread the load.
20180620_181237 by
Louis Walker, on Flickr
I drilled out the bootlid holes to 7mm to allow me some more lee-way for adjustment as it is a fibreglass replica and I wanted the fit to be as good as possible! Always had problems with the cup spoiler clipping the roof on shutting the boot.
Before fitting the brake light I noticed it was quite scratched, so I sanded it back with 1000-2000 paper and then machine polished it with some menzerna compounds.
20180620_181212 by
Louis Walker, on Flickr
20180620_181231 by
Louis Walker, on Flickr
The scrapyard where the light came from had marked the base with some tip-ex or similar and IPA would not get it off. A quick coat of Satin black soon sorted that out! Wasn't really necessary but I know it was there and didn't want any reflections back from below as it would irritate me. It's a spoiler off job to remove the light too.
Fit went relatively smoothly, however I could have probably done with drilling out the Boot lid more to allow for even finer adjustments as the spoiler slightly touches the roof when shutting the boot like my cup one used to do. I will also need smaller struts but it can go quite far up before touching!
And some pics
20180620_204239 by
Louis Walker, on Flickr
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Louis Walker, on Flickr
20180620_204228 by
Louis Walker, on Flickr
20180620_204224 by
Louis Walker, on Flickr
20180620_204202 by
Louis Walker, on Flickr
20180620_204213 by
Louis Walker, on Flickr
20180620_204219 by
Louis Walker, on Flickr
Very happy with the overall fit for a replica spoiler and how well the brake light sits in place. Needs a final machine polish now but should be easier on the car.