ネストされたクエリがある場合、参照範囲を把握できませんでした。たとえば、内部結合で NoCarsFound.CU を参照できないようです。結合で以前の結果セットを参照できない理由がわかりません...内部結合のON比較で以前の選択結果を参照したり、エイリアスを参照したりする範囲を理解していないと思います。
あいまいな列名「CU」も取得します
そのため、NoCarsFound.CU がわからないというエラーが表示され続けます。vwInvalidCars.CU などのストレート ビューを参照しようとしても、vwInvalidCars を理解できません。
create procedure [Rac].[GetCarStatDetails_sp]
    @Year int,
    @CarTitle varchar(30),
    @Company varchar(31),
    @CU varchar(12),
    @UserName varchar(50)
as
BEGIN
DECLARE @CarMatch table
(
    FaceValueTol varchar(100),
    FaceValueDesc varchar(100),
    Year int,
    CU varchar(16),
    PaintTypeDesc varchar(50)
)
insert into @CarMatch
    Select  temp1.FaceValueTol,
            temp1.FaceValueDesc,      
            temp1.Year,
            temp1.CU,
            temp1.PaintTypeDesc
    from    Rac.viewCarBase as temp1  
    join (select Username, userCars.CU from Nep.viewUserCars userCars where UserName = @UserName) as userCars on userCars.CU = temp1.CU
    INNER JOIN
    (
        Select  CU,
                from Rac.vwCarFactor carfactors
        where RiskFactorTypeID not in (334,553,34334,534,7756)
        Group by    CU
    ) as temp
    on 
        and temp1.CU = temp.CU 
        and temp1.PaintTypeDesc  = temp.CalcPaintTypeDesc 
    Where
        temp1.RiskFactorTypeID=4
        and temp1.[Year]=@Year
        and (temp1.CarTitle=@CarTitle or @CarTitle='<All>')
        and (temp1.CU=@CU or @CU='<All>')
SELECT  ProductID_bo,
        Coalesce(CarTitle_bo,LTRIM(RTRIM(CarTitle))) as CarTitle, 
        Coalesce(Company_bo,LTRIM(RTRIM(Company))) as Company, 
        Coalesce(CU_bo,LTRIM(RTRIM(CU))) as CU
    FROM
        Rac.viewCarBase as NoCarsFound
        join (select Username, userCars.CU from Nep.viewUserCars userCars where UserName = @UserName) as userCars on userCars.CU = NoCarsFound.CU
    LEFT OUTER JOIN
    (
        Select  ProductID_bo,
                CarTitle_bo, 
                Company_bo,
                CU_bo,
        from (
                SELECT  ProductID as ProductID_bo,
                        LTRIM(RTRIM(CarTitle)) as CarTitle_bo, 
                        LTRIM(RTRIM(Company)) as Company_bo, 
                FROM    Rac.viewCarBase
                join (select Username, userCars.CU from Nep.viewUserCars userCars where UserName = @UserName) as userCars on userCars.CU = Rac.viewCarBase.CU
                where   ProductID in (Select ProductID from @CarMatch) and
                        and (CarTitle=@CarTitle or @CarTitle='<All>')
                        and (Company=@Company or @Company='<All>')
                        and (CU=@CU or @CU='<All>')
            ) AS SUB1
        Group By    
                    CarTitle_bo, 
                    Company_bo,
                    CU_bo,
        ON
                NoCarsFound.CU = CarsFoundDeals.CU_bo
    where 
        and (CarTitle=@CarTitle or @CarTitle='<All>')
        and (Company=@Company or @Company='<All>')
        and (CU=@CU or @CU='<All>')
end