Yes. The getz will take 6.5 inch speakers. However, they won't fit the standard mounts. You will need to install a mounting ring.
You will need to adapt the speaker connectors to fit.
Installing some foam behind them in the door and a foam ring to seal them to the door card will make a huge improvement to the sound quality.
I used 25mm MDF rings to install mine and got some pre cut foam rings from an online shop.
The mdf rings need to be drilled first and then varnished to keep them waterproof, the door is not a dry place!