How to create hybrid ISO/UDF DVD?

I'm trying to create a copy of my BMW professional Nav DVD and adding in the UK speed camera database. There's a description of how to do it here on a PC. I've managed to do all the file editing and PERL script etc, but the problem comes when I try to burn it. The how-to uses Nero and creates a hybrid ISO/UDF disk using relaxed ISO restrictions to allow longer file names, but also states that the Joliet file system doesn't work. On Toast, the only option for longer file names when burning ISO is to use Joliet. I've tried burning it using just UDF but the disk was not readable by the car's system.
At the moment, I'm trying to use terminal to make a hybrid from a cdr disk image. Can anyone suggest another way if this doesn't work?!
Thanks in advance.

It worked!

Well, seems I was a little too hasty in predicting my own failure! It worked!

Am quite pleased with myself since I don't have any terminal/unix experience but managed to use a bit of common sense and a few tidbits here and there...

Ended up using the command:
hdiutil makehybrid -iso -udf -o diskname.iso diskname.cdr

Once the iso image was made, I simply burnt it using:
hdiutil burn diskname.iso

Amazingly, it worked and was readable by the car's DVD reader. Some slight errors in the actual data files in order to get the database in the right place now and I'll be laughing...