The Lamborghini Murceilago and Gallardo cannot be bought in the game’s store. The only way i found out that these cars existed was by discovering them in the auction house.
Are these cars unicorns, secrets, and why weren’t they availible to be bought? Are there any more cars like this, or is it a glitch?
Thanks!
^^ Even then, you’re bound to find every single car in the game in the Auction House, even the DLC ones. But, the DLC ones, you’ll need to purchase with actual cash. 
The Murceilago, RX7, BMW M3 E36, Buick GNX are won via Midnight Battle.
And the gallardo, you get it with the skill points. You can also win an old mini cooper and a bentley continental gt. It’s the only way ton get this car and the two other (for free)
Yeah, when I started playing back in September, I bought these cars and now have 2 of each. I wish I knew they could be won for free.
Mazda RX-7 seems to be the only truly rare car of these because of those legendary painters obsessed with buying all of them and reselling for millions…
EDIT: I was able to buyout one of stock RX-7s too, with a little patience… (I needed one without a body kit)
The rx7’s are far from rare. Everyone can get one for free every time they do some kind of update. You just redo the midntight battle. I got two that way and another dozen for 19-39k from the auction house.
Seriously? I didn’t know… I guess that’s a bug.
About Auction house, yes, you can buy anything there if you search for a while but there are no constant list of stock RX-7s that nobody bids on.