The tray is raised and doesn't sit flush against the chassis so it's hard to measure that way. It is also difficult to insert the tray if the spacer is attached to the shifter, there isn't enough clearance.
I measured the location of the front left shifter spacer rivnut in relation to the tray's left rivnut in the chassis, then transferred those measurements to the new plastic tray to make the cut. The hole in the plastic tray for the spacer could be any shape really, what you have to get right is the cutout in the rubber liner.
- Remove top center console panel (where the start button is)
- Remove factory manual tray (3 bolts under the rubber liner)
- Unbolt shifter unit from spacer.
- Unbolt spacer from chassis and remove it (front of the spacer is taller than the rear, keep that in mind when reinstalling and templating)
- Grab new auto plastic tray and cut an opening for the spacer to go through (I used the chassis rivnuts as reference as explained above to estimate where to cut)
- Cut an opening at the rear of the tray wide enough to allow the shifter arm to go through.
- Install plastic tray, secure with bolts
- Install shifter spacer, secure with bolts
- Add blue tape to top of rubber liner so you can draw on it
- Insert rubber liner under shifter unit
- Mark outline to cut, this may be tricky because there is movement to the shifter unit and you can't see the holes to line it up if the liner installed.
- Take out rubber liner and cut the opening, start small, adjust as needed.
- Install rubber mat
- Fasten shifter unit to chassis, making sure the rubber does not get pinched
Honestly, there was a lot of eyeballing, but it came out ok.