Ah right!. The SES module is voice control. It's a blakc box 1/2VHS size. Doesn't really matter if you have it or not.

The ULF does voicecalling+nav voice, the TCU does voice calling. Both are gimmicks.

You can't have an SES module and TCU/ULF both on at the same time, it gets confused. Either get/build an SES jumper plug (to jump the audio and mic) or use Navcoder + Resler interface (£50 ish) to disable voice in the ULF/TCU.

What you need to check is under the eject box. You are hoping to find a black FAKRA GSM cable and a 26 pin black quadlok (MQS) connector. This means you can drop in an eject box. Really early cars had a DB-something-else connector, or no connector at all.

In the boot, you are either looking at building (£15 ish) or buying (£60+US shipping) a DB25 to 54 pin adapter,
a ULF (GEN13) or TCU (Post mid 2004 - don't be fooled by BT logos, go for build dates) (£200ish),
a BT antenna (£25),
a bit of cable terminated in FAKRA and some brackets. (£40 all in)