I stumbled onto a little helpful information.
Quote
Of all human endogenous retroviruses known today, HERV-K is the only one that has been shown to produce viral particles. While the first of the approximately 30 HERV-K sequences integrated into the human genome more than 40 million years ago, evidence is accumulating that HERV-K was active more recently, provirus HERV-K113 being the youngest sequence found. However, it is unclear which HERV-K sequences code for the viral particles that are produced by human germ-cell tumours or melanomas. Here, we show that the provirus HERV-K113, cloned into a baculovirus expression vector, is capable of producing intact particles of retroviral morphology, exhibiting the typical structure of those particles that were characterized in cell lines derived from human germ-cell tumours. Thus, the HERV-K113 sequence is a candidate for particle production in vivo and for an active human endogenous retrovirus of today.
(bold is mine.)

http://www.ncbi.nlm.nih.gov/pubmed/18198388

So it turns out some are working on trying to demonstrate something in the real world.

Research results are "mixed"
Quote
Thus HERV-K113 is a credible candidate for causing disease in a manner comparable to infectious retroviruses. Genomic DNA samples from 951 patients with MS were tested for the presence of the HERV-K113 allele by PCR, with their unaffected parents (n = 1902) acting as controls. HERV-K113 provirus was found in 70 out of 951 (7.36%) patients with MS and was not significantly increased compared to the combined parent group (6.52%). The results do not support an association between this endogenous retrovirus and MS.


https://www.researchgate.net/public..._sclerosis_in_a_large_family-based_study

This next one seems confident
Quote
Here, we derived in silico the sequence of the putative ancestral “progenitor” element of one of the most recently amplified family—the HERV-K family—and constructed it. This element, Phoenix, produces viral particles that disclose all of the structural and functional properties of a bona-fide retrovirus, can infect mammalian, including human, cells, and integrate with the exact signature of the presently found endogenous HERV-K progeny.


Source

I notice a couple of things
1.) They custom "built" this virus, rather than simply catching one "in the wild". (I'm confident they didn't build it from scratch, of course.)
2.) They omit to claim it will infect germs and be inherited.

So they still have a 'ways to go. And for all the effort, if ERV's did in fact exist, they would, like so many other things, demonstrate design features for all the world to see - at least all the world that can wade through the language they choose to employ.

That doesn't seem to be deterring anyone much. Evolutionists are confident that "shared ERV's prove evolution", although there is some mighty peculiar "sharing" going on. Think "Bird Flu" and "Swine Flu" makes people part bird and part pig? The "strongest" part of the argument lies in the terminology, as usual. If they thought folks really understood what they were saying, they wouldn't be excited about this one at all.

Dark Matter + Dark Energy = Dark Truth

"We find that such evidence demonstrates that the ID argument is dependent upon setting a scientifically unreasonable burden of proof for the theory of evolution." - Judge Jones Kitzmiller case
http://www.talkreason.org/articles/Falsify.cfm

"To Compel A Man To Furnish Funds For The Propagation Of Ideas He Disbelieves And Abhors Is Sinful And Tyrannical." - Thomas Jefferson

"And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are the gift of God? That they are not to be violated but with his wrath?" - Thomas Jefferson