Listen to a CD or LP in showroom?

Department of Motor Vehicles?

It means District (Washington, D.C.), Maryland, Northern Virginia (i.e., D.C. and its suburbs).

Unfortunately that's how it is at a lot of dealers.   I demo'd my DAC through the Roon platform.  I didn't really like it's interface , but it allowed me to play way more tracks than I would have by bringing my material.   75 % of my listening is via Streamimg now anyway ...

A good dealer in my experience will let you listen to different sources if they know you aren't a tire kicker.  And that's one thing I never am.   If I visit your store, it's not to waste your time....and if I am a regular in your store it is the least you can do for me.   

I went to Natural Sound in Framingham a few months ago looking for a turntable.    They spun a few records for me.  It was a nice demo.   While I did not buy that Rega,  I did go back a few weeks later and buy the Ortofon cartridge I listened to because I appreciated their time with me.  

This discussion reminds me of the HBO show "The Rehearsal" where someone reproduces, with stunning detail, exact copies of various venues so that the client can practice a social interaction.

I don't see how ANY dealership now, or in the past, can come close to offering a similar set up to one's particular situation for an audition.  Yes, many dealers will have sources that are much better, or worse, than your own, and it is simply unrealistic to expect a lot of choices for companion gear in an audition.  Even if there were choices, how would you know which is the "correct" model for a meaningful comparison for your system?  It makes sense to use the best possible source, to reduce its adverse impact on the sound, when auditioning other gear in the system. 

You could try to arrange to either bring in your own gear, or arrange for a home trial.  I know that some of the dealers in the DMV will allow either if they know you or have some confidence in you.  But, don't expect an okay for a home audition of really large and difficult to move speakers or delicate turntables unless you and the dealer are REALLY friendly.  My favorite dealers are Command Performance (Falls Church) and Deja Vu Audio (Tyson's Corner)--both are very friendly and helpful and you can probably arrange for a meaningful audition.