Fraudulent safety for vehicle

So I bought a used car from a used car dealership. Said used car dealership took it and got it safety certified to be on the road at the time of purchase. On the receipt/ bill of sale it says “sold safety certified” so there is nothing indicating the car was sold “AS-IS”. Fast forward to last weekend I put it up on a hoist for the first time to do some work… found massive rot holes in the rocker panels - would NOT pass safety like this - I’ve had 6 mechanic shops 2 being safety inspection shops tell me there is no way this car should’ve passed safety and these issues were present during the time of inspection. The safety inspection done was only 14 minutes which is a red flag. On top of that the whole exhaust system is broken, it broke a week after I bought it so I took it back to the seller and he took it to the shop tha safeties it and all they instead of properly fixing it did was exhaust wrap the resonator Now my question is what legal actions can I talk? Do I have grounds to take them to small claims court or am I just wasting my time. I have already reached out to the seller to try and resolve this issue but they are not being civil so now I have to escalate the matter. On top of that all too it looks like the rust and rot has been sprayed to conceal the issues