I live in Omaha, and we have about 6 Menard's stores. The internet inventory said my closest store received one box of 24, but the manager claimed they never got any...zero, yet the innertube webpage said 18 on hand the first day. The manager said the online inventory was not real time, and didn't necessary reflect what was actually in the store.
I found one store who only had 8 left at 9am on the first day, only because the second buyer reserved the last on the shelf, but changed their mind. I happened to be at the cust service counter asking if they got any when when the person called to say nevermind. I opted for only 4, leaving 4 cars remaining for someone else.
They also had 1:43(ish) die cast cars (seemingly random models) for $4 each, and I scored 3 which fit my layout theme. The sales people said X-Mas special, they get what they get and won't get more this season
I have yet to try whittling the inside of the couplers, but that sounds like the easiest fix.
Like other members said,they are economical for projects.
One of these cars may need to be a stage for a (hobo?) band to set up on and have a track-side festival...
Cheers and Happy New Year
D.