Altering View in MS SQL Server by Adding Col based on Join
As far as some cars has not Year, you should use a LEFT JOIN on this way:

ALTER VIEW corvettes 
AS
SELECT    a.carID, a.carName, b.carYear 
FROM      Sheet1$ a
LEFT JOIN Sheet2$ b 
ON        a.carID = b.carID 
WHERE     a.carName = 'corvette'


Have a look at Using OUTER JOINS at Microsoft Docs.