The standard size of the front speakers in the R50/R53 speakers is 5 1/4''
Now, I had been informed that to fit larger 165 mm speakers, I would have to drill additional holes into my door skin.

This, I was unhappy about doing, as I was concerned should I need to claim for corrosion under warranty, Mini would use this as a 'get out' clause.

So, I decided to design and build my own high quality spacer rings, to fit my Focal 165KR2 speakers into the front doors of my Mini.
Using the original holes that fitted the standard factory fit 5 1/4'' speakers.

The spacer rings were made from dense Mahogany hardwood, as I wanted them to actually help improve the sound of the speakers.

They were coated in four coats of yacht varnish, to make them water/moisture resistant.

These spacer rings also allowed for the deeper mounting depth of the Focal 165KR2 speakers in the stock location.

Here are some pictures of the spacer rings.

 

Here are some pictures of the speakers installed in their factory positions.

 

One of the most professional jobs I'd seen. Nice job. They must sound really good. Where did you mount the crossover - I assume there is one.

 

Thanks for the nice comment!
I located the crossovers inside the car and ran the cable through the
rubber 'boot' that takes all the factory wiring into the door.
I wanted to protect the crossovers from moisture and the best way of doing
that is by not having the crossover in the door cavity.

 

Those speaker rings are probably the most solid part of your car!

Word of the day: fastidious !

 

Yup, they are absolutely solid!