Select Only Fields With Desired Variety

In order to ask my question on a SQL query I will use a simplified version of a table I was struggling with...

¦¦¦¦SHOP¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦CARS

KILBURN MOTORS¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦Mercedes
KILBURN MOTORS¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦BMW
KILBURN MOTORS¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦FIAT
BRIXTON AUTOMOBILE¦¦¦¦¦¦¦¦¦¦¦¦¦¦Mercedes
BRIXTON AUTOMOBILE¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦BMW
WEST HAMPSTEAD CARS¦¦¦¦¦¦¦¦¦¦¦¦¦Mercedes
CAMDEM MOTORS¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦FIAT
NORTHERN LONDON CAR-STORE¦¦¦¦¦¦¦¦¦¦¦BMW
NORTHERN LONDON CAR-STORE¦¦¦¦¦¦¦¦¦¦¦FIAT

So my question is: how can I select only SHOPs which have no CARS variety (e.g. a variety =1)?

In other words I am looking for a Query that would give me this outcome:

¦¦¦¦SHOP¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦CARS

WEST HAMPSTEAD CARS¦¦¦¦¦¦¦¦¦¦¦¦¦Mercedes
CAMDEM MOTORS¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦FIAT

...because WEST HAMPSTEAD CARS, selling Mercedes only, has a CARS variety equal to 1 as well as Camdem Motors which sells only FIAT.

I tried with this query:

SELECT DISTINCT SHOP, CARS
FROM CAR_SELLERS
GROUP BY SHOP, CARS
HAVING COUNT(CARS) = 1

But it doesn't work.

In addition I also would like to know for example how to create a similar query for a different desired CARS variety (e.g. 2, 3...)

How to do the tabs or attach images in the Post New Topic Message box... I wanted to attach a screen shot of the table but I was not able to and so, in order to post my question, I prepared a simplified version of the table plus I had to do the tabs/spaces manually with the symbol (¦)