This week, the ratings of 4 Auto Components stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Magna International Inc. (MGA) experiences a ratings drop this week, going from last week’s C to a D. Magna International Inc. designs, develops, and manufactures automotive systems, assemblies and components, and engineers and assembles complete vehicles. For more information, get Portfolio Grader’s complete analysis of MGA stock.

Gentex Corporation (GNTX) earns a D this week, moving down from last week’s grade of C. Gentex Corporation designs, develops, manufactures, and markets proprietary electro-optic products, mainly for the commercial building industry. For more information, get Portfolio Grader’s complete analysis of GNTX stock.

Dana Holding Corporation (DAN) declines this week from a D to a F. Dana Holding Corporation is a supplier of axle, driveshaft, structural, sealing and thermal management products for global vehicle manufacturers. The company also gets F’s in sales growth, earnings growth, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of DAN stock.

Spartan Motors, Inc. (SPAR) gets weaker ratings this week as last week’s C drops to a D. Spartan Motors, Inc. designs, engineers and manufactures custom heavy-duty motor vehicle chassis and bodies. The company also gets F’s in earnings growth. For more information, get Portfolio Grader’s complete analysis of SPAR stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.