If your Dash looks like this one, this mount will fit.

Note: This Dual Dash Conversion Kit is designed to be able to mount two graphs, side by side on the factory dash. The kit is designed to hold different combinations of graphs and is very versatile to meet your needs. On the right-hand side of the dash, we moved the 2 large gauges down to the bottom of the BBT mount for easy viewing and we raised the graph position to equal the height of the left side dash graph. The new Conversion Kit has a one-piece main plate that can only fit in one place for easy installation. The left side of this mount starts just above the steering wheel main mechanism, so you do not have to remove that to install the new dual mount. The main shelf will accommodate the graphs you choose from the drop down box.

Disclaimer: In most cases on the Sonar mounted on the Left side of the conversion kit, a 1 1/2" Vexus 3 screw steering spacer will be needed to get more room between the top inside edge of steering wheel and Sonar face. You can get it here -  Vexus VX/DVX Steering Spacer