2005 S60 2.5T AWD with 45,000 Miles

A couple of weeks ago, I was driving in traffic and the car felt very sluggish.
I checked the gauges (RPM, Speed, Oil, Fuel) and all were off. Even the gear display said "-".
Traffic speed up (so did I) and I could hear the engine reving high. I tried to shift with the manual mode but nothing happened.

Luckly, I was near a Volvo dealer. I parked the car and when I started it up again to drive into the garage, everything was working. They ran a 3 hour diagnostic test and found nothing wrong. Oh, and my warranty ended a month prior so they gave me a $200 bill.

It has not done it since but I'm worried that it will happen during a road trip with my kids.
Did anyone else have a similar problem?

Thanks

 

Sounds like a bad connection somewhere intermittently.