Formula Too Long Problem

Pl see file
In C3

=SUM(INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),1)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*0,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),2)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*1,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),3)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*2,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),4)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*3,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),5)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*4,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),6)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*5,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),7)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*6,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),8)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*7,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),9)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*8,COLUMNS($C3:C3)-1)),0))+INDEX('Parts Table'!$D$3:$M$10,MATCH($B3,'Parts Table'!$B$3:$B$10,0),10)*SUM(IFERROR(MMULT(1*('Parts Table'!$N$3:$AG$3>0),OFFSET('Units Sold by Model & Market'!$C$3:$C$22,21*9,COLUMNS($C3:C3)-1)),0)))