mmm, not diecast but still very cute, those 1951 Buick Le Sabre, any idea of the manufacturer? 
hard to find, I guess...  

no idea no markings on any of them 
That Corvette camper looks like a attachment you'd hook onto a trailer hitch 
Someone came out with a camper that would attach to the top of the roof of the car 
Also I seen a Beetle camper 
Owner said top speed was 50mph 
Sounds very underpowered to me