This model is a copy of Politoys #54. It is made from hard styrene plastic and comes in several different color variants. It is among the very early KDN (Kaden) models, launched around 1971 (the license plate reads "KDN-71" like it did on all the early models)
The model is a lot heavier than it looks, this is due to a large piece of metal ballast attached to the top side of the baseplate. It remained in production for several years.
Mini Auto was KDN's 1/43-ish range. Because many of the early models were copies of Politoys and Norev models, scales varied accordingly. This A40 is scale 1/41.
KDN and Kaden are the same, or rather: KDN is short for Kaden, and during early years, the name KDN was used, but nowadays, the company (now having switched to diecasts) uses the name Kaden.