A few years back, for about maybe 6 months, they did list out the location of A B C etc... but they stopped doing it.
I have seen the same bizarre scenario that gto4ever described, many times.
In most cases it was a better option to buy the offending part that caused everything to do a switcharoo - from eBay Buy-it-Now with free shipping.
And get the rest of the main items from RA.
Another oddity i have hit a few times is shipping on gallon containers of synthetic lubricants.
Up to 6 gallons can ship for the same cost as 1 gallon ($9.00)
Try doing that at your local FedX
All in All - i love RA
And hate The Big 3 auto part chain stores