I am in the market of 2005 SL500.

After checking out 2 SL500's(both 2005), I found one of the cars has this option, but the other doesn't.

I know on SL55 AMG, they all have the gear change buttons on steering wheel.
But for SL500, 2005 model year, is this an option or due to the production date, they put on as standard?

Thanks.