Models such as these are difficult to identify and often comes down to studying the style of the letters used in the printing of words such as 'POLICE' and the 'JAPAN' on the base. Your particular model is clearly very crudely designed and made so is at the cheaper end of the market and Two companies that produce such basic tinplate cars are 'NOMURA' and 'ICHIMURA'.
Both these companies had wide product lines catering for all sectors of the toy market. Ichimura was also making toys for many of the well known Japanese brands such as 'YONEZAWA', 'SSS INTERNATIONAL' and even that mighty toy company 'BANDAI'.
The American 'CRAGSTAN' company marketed Yonezawa and Bandai toy cars in slightly reprinted boxes. They used the brand name, 'Gragstan-NGS' for Japanese exports (Nipon Goraku Shokai) made by Ichimura among others!
There is every chance your model above is by 'ICHIMURA' (Ichimura Shoten' being the actual stock supplier), but not carrying their brand name or logo as it has many of the basic hallmarks of a cheaply made toy for use by a general toy distributor and we may never know who that was, but at least we had a good guess at it!
Thank's Johnboy, nice bit of searching. 'TN Toys' is 'Toy Nomura, one of the brands I mentioned in my assessment, so I think we have cracked another mystery toy for "braintrust"...