BONDO can be used on wood and anything will stick IF you seal it proper. In my past (this life) I've done wood and auto fillers and learned how to QUICKLY seal each.
Bondo on wood. Use a rattle can of bare metal "red primer". Let dry and sand smooth or TOOTH of your choice, second coat if you sand through.
Now you need one coat of any mid to good quality rattle can finishing paint, let dry and sand off any bumps.
NOW your Teardrop's surface is ready to finish. This seems like unnecessary steps but it's the quickest and lowest cost I know. Also you'll be using up old car paint leftovers, I still have some from the 80's... still good cause it's oil base.
HOPE THIS HELPS,... someone.