Can rear main and oil pan leaks cause oily film on rear windows? 03 Tahoe

What is your question?

Uses 4 qts.oil in 1200 miles. Now there's an oil film on rear windows and doors. Chevrolet dealer said no transmission leak. I've scheduled rear main and oil pan leaks for repair.

How long has your 2003 Chevrolet Tahoe had this problem?

Just bought it