For my 08 XKR they are the quarter turn type. I did a quick search for quick comparison and found this which looks similar on ebay

ENGINE COVER SCREW (QUARTER TURN) - Jaguar X-Type / S-Type / XJ6 / XJ8 / X350 | eBay

Maybe start a combined search for best place to get these...

 

Looking for these?

 

I think Wooky is talking about the cover over the engine that has 4 metal quarter turn bolts with phillips heads...

 

Guys I've just found this thread. This fastener is a standard Ford part, I have a few in their original bags at the hangar. I'll get photos and part numbers for you this afternoon.
You can buy this at your Ford dealer.
Regards,

 

I checked at my local Ford dealership, these sell for $2.28 each there.
Ford Pt# W706519-S300

 

ClipsAndFasteners.com - Automotive Retainers,Clips and Fasteners

 

Thanks, J5hort, that is the one I am looking for. I bought a box of the plastic ones from Clips and Fasteners a couple of months ago but have been unable to find the ones for the engine cover.

 

Yes correct

 

Received my A20518 retainers from clipsandfasteners and installed them. I only had one per side panel left on there. I swear the car is faster now.

 

^^^haha

 

For anyone in Australia looking for this item, I just collected from Alto a main Jag & LR Dealer in Sydney 5x LR024316 for the grand sum of A$2.13 each or around US$1.60 each obviously a Land Rover part number but exactly the same item

 

Just did my order. I also picked up 50 of the 1/4" push pins for the radiator covers. I also found that if you use Facebook as a coupon it gives you 5% off.

Link for the push pins.
Splash Shield/Fascia Retainer Fits 1/4 Hole

 

Get them here as well.

 

No end to what we can get online using Al Gore's internet! How did we survive before?

 

Thanks for posting the link to ordering these fasteners, I just ordered a pack. I don't think I've seen an XK with a full compliment of these under the hood.
Ron