Where do I get actual optical clear side markers, not clear?
 

I've ordered the clear marker lights from ebay and received one that looks perfect and one that looks like cheap plastic. Too clear. I can literally see the bulb and the chrome housing through it. The other obscures the housing as it should. He sent another lense and it was also too clear.
Now I see adamesh has the same uber clear lenses on their markers.
Does no one make the proper lenses any more?

I got a set from XKZ in the UK. It's been several years ago but Have been very happy with them.

Lenses:
2 x Jaguar XK8, XKR Clear Side Bumper Reflector Lenses (2 pieces) | eBay

His store:
Jaguar Performance Parts, Jaguar Accessories items in XKZ Parts and Accessories store on eBay!

Attachment 56593
That's who I got them from. When I contacted him, he said the one opaque one was the old style and everyone wanted them cleared. His photo shows the older style which IMO is a much better quality lens. It's more factory looking and the new style is much cheaper looking and the interior of the marker is totally visible.
If you bought them over a year ago, you got the older style. I had to use a window frost spray on the inside to obscure the bulb, I use led bulbs, but there's no sparkle now like the older style would have had.
Oh well!!!

Blacked mine out
 

I got a blacked out set from Adamesh but think I could have just used heavy spray on window tint (which is what they appeared to have done). On your car, blacked out would likely look better anyway.

I just installed a set from XKZ also, along with chromium bulbs from Hoen. Look great.

See my avatar.

Attachment 57427
Mine are on. I had to spray the insides with window frost to get them to match. Not thrilled. Also, some chrome came off when removing the amber lenses and it shows the yellow plastic through the clear around the outer edge. Ugh. Ordered the chrome bezels to hopefully hide it.

Yes you can get the genuine part from DCR Autoparts...