I drive G35X - 'VDC OFF' and ''SLIP" lights are

Quit guessing and have ABS codes read. Symptoms would be indicative of a bad wheel sensor which often fail with hub/CV failures.

NO, its NOT SAFE TO DRIVE. Your car may loose power in the middle of the intersection and then what? VDC and Slip light may be related to ABS system, please have it check.

YOU MAY HAVE A LOOSE UNIVERSAL JOINT ON YOUR DRIVE SHAFT. IT IS VERY DANGEROUS TO DRIVE IT WITH A LOOSE DRIVE SHAFT.... IF THE FRONT OF THE DRIVE SHAFT COMES DISCONNECTED, IT WILL DIG INTO THE PAVEMENT AND CAUSE A POLE VAULT ACTION... AND OVER TURN YOUR VEHICLE.

Is VDC switch turned on? If not check brake fluid level

See if the following information helpful:
1. Keep an eye on the dashboard for the indicators marked "SLIP" and "VDC Off" which will tell you the status of the computerized handling system if handling isn't normal. "SLIP" will blink when VDC is operating. "VDC OFF" means the system is off. Turn the VDC system back on if the Nissan's handling is poor by pressing the "VDC Off" button until the light goes out.

2. Adjust your driving if "SLIP" comes on. "SLIP" means the road conditions may be slippery. The VDC aids in steering and stopping, but be careful, even if VDC is engaged.

3. Remove any aftermarket suspension parts like enhanced shock absorbers if the "VDC Off" light comes on and handling is bad. The VDC system is geared for stock equipment and tires only. Use winter tires or snow chains on snow-covered roads. VDC won't substitute for the correct winter equipment.

4. Don't drive on very inclined corners with high banks and leave the VDC switch on if the handling is poor with VDC on. The system can't operate properly in that environment. Disengage VDC, or avoid those kinds of roads.

The first time this happenned to me I wondered as well. It also happenned during a coold snap. Turned out the VDC light on is a warning for the brake system when the pads need to be replaced. Had the brakes done and the light went off. Happenned several times. -2004 G35X

sounds like the battery went died and the system where going into limp mode til it ran out of power with a good battery installed check the charging system output

I have a 2005 Nissan Pathfinder, the VDC light and the "Slip" light came on the dash, and the slip light was coming on while i was driving at the speed of 20 mph

All three lights came on at the same time while I was driving last month. The dealer said it was the sensors. Had them replaced for about $750

I found your answer here:

Why Does the SLIP Light Come on?
The SLIP light represents the vehicle's traction control program. When illumiated it takes over control of throttle and braking based on input from a myriad of sensors. The VDC (traction control) is initiated by wheel slip, yaw and any other factors that make the computer think you're on the verge of loosing control of the vehicle. There have been a lot of complaints about the G35's VDC being too interferring and actually causing harder driving conditions. The VDC can be turned off via a switch to the lower left of the steering wheel (useful if trying to pull out of a snowy spot when wheel spin is necessary, or "spirited" accelerating). Even with the VDC turned off, however, it will still kick in if it detects substantial loss of control. NOTE: if you plan on racing, turn the VDC off. Otherwise it will ****** the throttle when you chirp the wheels from 1st to 2nd gear.