Lately I've been noticing from the tach that when I'm idling in "D", the rpm's are at 500rpm's & I feel a 'lil bit of a shake coming from the low idle, is that idle speed a bit too low?

BTW this is w/ an auto. trans

Thats a bit low. Have you cleaned your throttle body out lately? That usually brings things up to speed.

I'm planning to do the fuel induction cleanup at my dealer soon

Mine was idling at the same speed and I did a TB cleaning plus changed my fuel filter and PCV valve. At first the car would idle at 600 RPM but then after a few days it started to fall back to 500 RPMs again. Is there anything else I should consider?

my car idles at 500 too sometimes but it doesn't shake
it jus feels real sluggish off the line
btw i too have an auto

I have the same thing, I cleaned my TB and it was reving higher but then after a couple weeks it dropped back down to 500. Hmmmm.....

You could try to tighten your tb cables, don't make it to tight, but make it tight enough so that your cable don't sag as much. Kinda confusing but you kinda get the idea.

How would I tighten my cables?

Mine (95 auto) wa idling at around 500 - 600 when warm (and in park) until I cleaned throttle body, and changed fuel filter. Now it's idling at around 700-900 when warm. Is this the "right spot"? I was thinking something was wrong when it was idling higher even when warm...

Greg

Throttle cables have nothing to do with your idle speed. Tightening them up will take the play out of your gas pedal.

If your idle isn't around 600 in D, you should do one of two things:
1) Clean your Idle Air Control Valve
2) Adjust your default idle speed

Instead of making this a long post I'd rather just say

SEARCH IS YOUR FRIEND