Don't feel badly. You were probably in a pinch and these people are open 7 days a week.
I get a kick out of all of the Bosch plugs wires. etc. that are stacked mile high behind the counter. I recently asked to see a set for my 103 motor. No way these are close in quality to the Beru's or for that matter Bosch wires sold at real euro parts houses.
The mass-marketers are ok for oil, windshield wiper fluid, etc. but not for anything like pumps, alternators. etc.
1991 300-SEL - Model 126
M103 - SOHC
James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.
Liberty Firearms Training - After years of trying to regulate California criminals with a never ending stream of gun control laws they have still not given up with the belief that if they make something a crime that criminals will miraculously start obeying the law.