From what i've heard Cadillac Catera's are unreliabile. why are they unreliabile?

[Alec]

Cadillac Catera

 

[Jenny Smith]

because it is made by an American company.

Trouble Spots
Consumer Guide's® Auto Editors have scoured repair bulletins and questioned mechanics to search for commonly occurring problems for a particular vehicle. In some cases we also give possible manufacturer-suggested solutions. In many instances these trouble spots are Technical Service Bulletins posted by the manufacturer, however, we have our own expert looking at additional vehicle problems.
Brake noise: The rear brakes make a squeal when backing up and redesigned calipers cure the problem. (1997)
Climate control: The climate-control display goes blank or goes off for several seconds. (1997-98)
Dashboard lights: The antilock-brake light and traction-control light activate because of a wiring problem. (1997)
Dashboard lights: Due to a problem with sensor or wiring, engine temperature gauge may falsely indicate overheating. (1997-00)
Oil leak: Oil leaks from timing cover due to leak at oil pump gasket and/or oil galley plug behind cover. (1997)
Tire wear: Original alignment settings have been blamed for premature tire wear and the car drifting or leading, especially to the right. (1997)
Tire wear: Premature tire wear and alignment problems can be corrected by revised alignment specifications. (1997-98)

 

[Bobby Jim]

The Cadillac Catera is based on one of General Motors foreign car companies. Opel is a European Car Company owned by GM.
Opels do not generally come up to the luxury standards people expect from a luxury brand, so what Cadillac ended up with was a substandard car that people had high expectations of.

A couple decades prior, Cadillac tried the same thing during the oil/gas crisis of the 70's & 80's, marketing the Cadillac Cimmeron, which was based on the Chevy Cavelier. Leather, gadgets, and sound proofing do not make a piece of junk a luxury car.

The Catera is a nice car, and as reliable as any Opel product.
The problem is that such cars are hybrids, borrowing parts of one to make another.