Looking good mate, regarding the brakes your mates probobly had a v6 brake upgrade..
Nope not possible mate, V6 runs 5 stud fitment..
All I have found out so far is that vauxhall ran a 22mm and a 24mm thick disc, there is no rhyme or reasoning as to which they used on the late mk3 Cavs as most were built from the parts bin..
Mine is a odd one, it has thrown up many questions and all we can figure is as one of the last Cavs it was built from that parts bin, either that or someone has skimped on replacing parts over the years.
Also now fitted my Astra mk4 front splitter, I believe it to be the only Cav wearing one online at the moment.
Looking lower already...Lol




lol
looks just like this same colour on a K 
