Using mobile handset rather than bluetooth

[antspants]

On my route to work this morning I spotted a couple of potential candidates for the Supercars photos thread, one being an orange Mclaren MP4 and the other a very nice purple GTR (not a rare car but a nice colour I hadn't seen before).

In both cases I had my phone ready to snap away and in both cases decided not to as the owners were both on the phone with handsets held to their ears.

Now I've never been lucky enough to own either of these cars, but I'm assuming for the money they cost that bluetooth connectivity might just be standard.

If so, why drive along using the mobile handset itself?

I'm no great keyboard campaigner for road safety or particularly against the use of mobiles in cars, it just struck me as a bit of a strange coincidence.

[CraigMST]

The early MP4's did have computer software problems but not too sure if that issue is fixed now.
Could just be lazyness. Lots of cars have bluetooth nowadays but people still choose to have the phones to their ears.