pptra & sneaky taxes

if your car is "garaged" in arlington county, you owe the county a 4.4% tax, unless you can prove you’ve paid a similar tax elsewhere. you also owe a decal fee of $24 for the honor of proudly displaying proof of your good citizenship. due to something called the personal property tax relief act of 1998 (pptra), the tax is reduced by 70% if the car is used largely for personal transportation.

however, as with most things, all is not as it appears. arlington county is not having to make due with less because of the pptra. on the back of my personal property tax bill:

Your tax bill has been reduced by 70% on the first $20,000 of the value for qualifying vehicles. Alrington County will be reimbursed by the Commonwealth for this amount, once you have paid the balance due shown on your tax bill.

from my understanding of this statement, virginia state taxes are used to subsidize arlington county taxes, which seems like quite a strange thing to do, especially for a county actively encouraging its citizens to be car-less. basically, people out in lee county are paying part of my tax bill (an aside: when looking at a map to choose a county to reference here – yes i’m that big of a nerd – i noticed there are two counties next to each other, one called patrick, the other called henry. cool).

i'm not sure of the origins of this arrangement. this is all i could get out of the office of commissioner of revenue (vehicle@arlingtonva.us):

If a vehicle is used for personal use then the state pays 70% of the taxand the taxpayer pays the remaining 30%.

i doubt if one or two emails count as investigative journalism, but what do you expect for free?!