-- you only need to read the SalesGLLink table once:
INSERT INTO #TempSalesGLLink(
StoreId, LocId, SalesGLLinkUniqueNum, SalesTypeCd, LineCd,
VehSaleAcct, VehSaleDept, TradeACVAcct, TradeACVDept, OverAllowAcct, OverAllowDept, LoanDiscountAcct, LoanDiscountDept,
DueFromFinAcct, DueFromFinDept, CashDownAcct, CashDownDept, CostGoodsAcct, CostGoodsDept, InvSoldDept, OtherIncomeAcct, OtherIncomeDept, DueToCustAcct, DueToCustDept, NSFFeeAcct, NSFFeeDept, NSFRecAcct,
NSFRecDept, CostofSalesSubAcct, CostofSalesSubDept, AHInsRevenueAcct, AHInsRevenueDept, AHInsCostAcct, AHInsCostDept, CLInsRevenueAcct, CLInsRevenueDept, CLInsCostAcct, CLInsCostDept)
SELECT
StoreId, LocId, cj.SalesGLLinkUniqueNum, SalesTypeCd, cj.LineCd,
VehSaleAcct, VehSaleDept, TradeACVAcct, TradeACVDept, OverAllowAcct, OverAllowDept, LoanDiscountAcct, LoanDiscountDept,
DueFromFinAcct, DueFromFinDept, CashDownAcct, CashDownDept, CostGoodsAcct, CostGoodsDept, InvSoldDept, OtherIncomeAcct, OtherIncomeDept, DueToCustAcct, DueToCustDept, NSFFeeAcct, NSFFeeDept, NSFRecAcct,
NSFRecDept, CostofSalesSubAcct, CostofSalesSubDept, AHInsRevenueAcct, AHInsRevenueDept, AHInsCostAcct, AHInsCostDept, CLInsRevenueAcct, CLInsRevenueDept, CLInsCostAcct, CLInsCostDept
FROM SalesGLLink s
CROSS JOIN (SELECT SalesGLLinkUniqueNum = 6, LineCd = '4' UNION ALL SELECT 7, '5') cj
WHERE s.salestypecd = 'r' AND s.linecd = '3'
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden