Hi Dan
Thanks. Though that confused me a bit! Let's take 1 more step backwards for overview.
As everything is relative; We must consider ALL motion in space wrt the local CMB rest frame. ..So.. when you say; "with the exception of cosmic rays..." ..you need to go back a step and re think. In space that 'exception' is in fact the rule!
If we're in a different background medium (gas, i.e. air, water, or an insulated' vacuum like the LHC pipe) V is measured wrt that.
And also remember ALL massive bodies (even tiny ones!) have a non-zero magnetic potential, and a fine structure, - constant at rest only!! - of charged particles, the orbiting or free electrons /photoelectrons.
Now we can start again with that rule. As Einstein said; All mass is "spatially extended". i.e. we must consider a bit of the space around matter as, inertially, part of that matter. This means by definition it does NOT move with respect to the matter. It can't, so neither can it's 'boundary' position. But the solution to your problem is; In space, the whole caboodle is ALWAYS in motion wrt the CMBR. (or vice versa - that's relativity).
Plasma is anyway supposedly 99.9% of all matter, so forget the conventional 'neutral particle' approach - it's a red herring. We're talking for instance about our ionosphere and plasmasphere, which are related to our magnetosphere, in the EARTH's rest frame. Venus is the same; see.; Echim, M., et al. Comparative investigation of the terrestrial and Venusian magnetopause: Kinetic modelling and experimental observations by Cluster and Venus Express,Planetary and Space Science May 2010.
DOI: 10.1016/j.pss.2010.04.019
And yes, the greater the relative v the thicker and higher frequency the shock, which is because it has to slow down and change the em wave frequency more, which refracts (diffracts) it more. (Doppler shift - or 'Stokes/Anti-Stokes scattering PMD'- is evidence of the speed change). See the NASA Heliosperic shock, I think it's in one of my previous papers, try; http://vixra.org/abs/1007.0022
Light goes through a plasma cloud at c/n wrt the plasma cloud, which has a non zero n. Simple really!
This is a 3rd way, between an 'absolute space' and 'no ether'. it gives; "infinitely many 'spaces' in relative motion". And who said that in 1952? - the same guy who said "Space without ether is unthinkable" - one A Einstein.
My current paper is about how this affects cosmology. Black holes are toroid 'Tokamaks' which recycle galaxies and spit them out as plasma (Quasars - jets) explaining half the issues in science! re-ionosation, Chiral polarisation etc etc etc. But also means every bit of each of us has already done the Star Treck 'beam me up' thing at up to 7c (M87) at least once, and will do again in only about 5Bn yrs. It's all about recycling!
I know that's close to what you've found, as is; That the universe and 'big whoosh' was a scaled up version (on the axis of evil), powered by the previous universe, but further, this means we may be, and have been, eternally recycled, and even that when we die, if time goes quick, the next time we wake up we'll be some other organism. - and all via science!!
You see I left out the reeally provocative bits as most might find them a bit scary! But obviously it's not a perfect system, and we both have some brain cells that didn't get totally wiped by our last re-ionisation so we remember how it works! Either that or we're nuts of course! I shouldn't have worried, few will read it and even fewer understand it, there are too many dynamic variable for most human brains.
Did that all slot into place for you? Do just ask more if needed.
Best wishes
Peter