Toyota and Lexus Engines develop engine oil sludging slowly over time. 2006 Class Action Lawsuit cited Toyota at fault. Toyota agreed to warranty all cars up to eight years from original purchase. Problem: Most issues with engine sludging requires in excess of 100, 000 miles to present itself. Most low mileage drivers do not hit the 100, 000 mile mark until the warranty period has past. Toyota requires extensive proof of oil changes to "confirm" that you properly took care of your automobile's maintenance. Oil changes are the cheapest and most common maintenance procedure at under $50 per change. Most people do not keep oil change receipts and rarely use the same location if not completing the oil change themselves. Without proof of oil change history, TOYOTA refuses to honor sludging problem. Fix requires engine replacement and cost averages $4000. Over 337, 000 Toyota manufactured after 1995 have this problem. Beware, Toyota is more willing to spend $millions advertising the quality of their products, but not spend even 1/10 of 1% of that to keep loyal customers, but instead place the blame on customers who have spent from $15, 000 to $45, 000 on a new Toyota to be told that they didn't care for their Toyota and therefore can now, eight plus years later contribute to Toyota bank accounts because the once GREAT JAPANESE QUALITY company doesn't HONOR it's products any longer.