Is it possible to remove the space saver spare from my 2005 Cayenne and replace it with a full size 20" wheel, just don't like the space saver as a spare.

 

Uh, no. That's why the "space saver" is there

 

and we’re done here.

 

You'd have to have the big spare in the cargo area.
Kinda like mid-70s Blazers.

No way in the world it will fit under the floor.

If you choose to go that route, make absolutely certain that it's secured. There's enough mass in a wheel to kill people if it flies forward in an accident.

 

Yes we are done here.......

 

Another option is the rear tailgate mounted swing away spare. I know this was an option on the 955, but not sure about the 957 (maybe the Transyberria), but maybe you can find that assembly on ebay or at a parts dismantler.

 

Easy solution if you want a full sized spare: get a wilco hitchgate solo high clearance...

https://www.wilcooffroad.com/shop/hitchgate-solo/

 

thanks for the reminder to again exercise mine next oil change