I recently bought a 2003 R50 Hatchback and looking around the car I noticed a relay was missing from the fuse panel. So I went to the parts store and this is what they gave me:

Bosch 0332019457 Multi-Purpose Relay

My question is: the other original relays to the car have a middle prong (4+1) and the new one doesn't. Just the 4 prongs as in the picture. The car seems to run fine so far. How worried should I be?

 

Well, without actually knowing which relay you added, it's impossible to say. You probably just added a relay for an option your car doesn't have, like the shift lock or headlight washers, in which case it's doing exactly nothing.

 

Get the part number off of the missing relay, insert that into a Google search, purchase, install.

Autozone should be avoided for parts for a Mini, unless generics are explicitly known to work in lieu of quality, German, components.

Any of the German automaker's cars get annoyed with low-quality parts being put in place of OE or OE-equivalent replacement parts.