Have heard back - Note that I am passing this info onwards simply as a FYI; I have no affiliation.
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Sorry for the delay in getting back to you, it took a little time to dig out the information. We last made the kit in 2015!
In answer to your question, yes, we make a larger disc conversion for the 318mm front disc setup.
We can supply the kit, which comes with:
1x pair of 338x28mm plain/grooved/dimpled/drilled, black/silver/gold antirust coated discs
1x pair of custom caliper adaptors
1x set of longer bolts
1x pair of spigot rings for the discs
The total price for this kit would be £289.00 plus shipping.
If you'd like to order the kit, can you send the payment via PayPal to
sales@freakyparts.co.uk (as friends/family or covering the fees) and follow it with an email to the same address with the order details and delivery address and I'll get a kit sorted for you.
I've attached a picture of the kit as fitted to a previous customers car.
thanks
Stewart
FreakyParts
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Seems like a very cost-effective upgrade, particularly for anyone who is due for a pair of new front rotors anyway.