Positive Grounded Radio

Hello..

I bought a 94 Laguna last month, but it has no car radio in it. The battery is positive (+) grounded. Does this mean i have to buy a positive grounded radio or can i insert any radio? Or do i need a transformer or converter or something to stop the radio blowing up if i put a normal radio inside, because i have got a couple of radios but they all have a negative (-) sign next to the grounding on the information panel?

Any help much appreciated..

Does your car work?

Positive grounding nowadays is unheard of... I only found out earlier this week of of only one car being positively grounded and that was a mini back in the eighties or something....