Я хотел бы предложить это:
DECLARE @Text1 NVARCHAR(MAX) = 'This is the 1st time I found the Car# CAR:8 #NumberIncluded#'
DECLARE @Text2 NVARCHAR(MAX) = 'This is the 1st time I found the Car# CAR:8 #NumberIncluded# with no ID tied to it, the prices is 588USD for CAR:7 #NumberIncluded##NumberIncluded#'
DECLARE @Text3 NVARCHAR(MAX) = 'My CAR:A5, CAR:9 AND CAR:10'
SELECT SUBSTRING(@Text1, PATINDEX('%CAR:[0-9]%', @Text1) + 4, 1)
SELECT SUBSTRING(@Text2, PATINDEX('%CAR:[0-9]%', @Text2) + 4, 1)
SELECT SUBSTRING(@Text3, PATINDEX('%CAR:[0-9]%', @Text3) + 4, 1)
Ожидаемые результаты : 8, 8, 9