the last ones were blurry because i had the shutter speed too slow ... the monitor makes a huge difference also... they dont look blurry at all on another monitor
Are you using a CRT monitor from 1998? I'm sure Squeek (KDMTyte) was at work when he saw these which means he was using a regular flat screen monitor, nothing fancy or expensive. I'm at my house and looking at these on a iMac (2009) monitor and they all look as blurry as can be....not just the last ones....all of them.
1/60th of a second is not slow at all for automotive panning shots. It's about where you should be at. Ask Guy or Roly; we've been at events where we take it down to 1/25th just for shits and giggles and our worst shots come out better than these.
I'm surprised you haven't blamed it on having an older model SLR (Nikon D70s), but then I would bring up the fact that Roly was using a base model Canon XTi and Guy was using a Nikon D50 which is just as old as your camera and a lower model, and both of them were producing better pictures back in the day.
Bottom line is don't make excuses. You need more practice panning and that's all there is to it. A lens that goes further than 80mm would be better too. The older plastic mount Nikon 70-300mm is super cheap, you should pick one up. Also framing could be a little better, but that's just my opinion.
Good luck sir!