I never had a starter problem, maybe because we’re in Florida, but the X1/9 had it’s engine in the rear, and the battery was in the front trunk. Which meant that you had a really long battery cable to the starter. It ran the length of the car thru the tunnel in the center. It had a compass on the dash, and every time the starter was engaged the compass would automatically align with the magnetic lines of the current flowing in the cable!...........
I recall a pal from 1977 owned one of these. He put two starters in the thing between ‘77 and ‘80.