good to see you bought it back.
fancy car hauler.
sorry cant help, probably something minor.
Some help please...
I blew up the coilpack mashing the car pretty hard so i bought a $60 off amazon and replaced it. I also got some new NGK platinum dual spark plugs. Now when I hit about 3-4.5k RPM the car stutters or lags, then it catches up and back to normal. what could it be? the cheap coilpack? spark plugs? The car was driving fine before.i'm stumped
Do the good 'ole spray bottle test. Could be arching.
Check wiring, specifically, engine harness barrel connector and wires, to include engine grounds. Any wire could have take damage (small shrapnel) when it blew off, if so the plug wire may arch after. If no faults found, likely you are still arching somewhere. Pull all connectors, clean then dielectric grease it, reapply and be sure all wires are fitted tight. Spray bottle test if a no go after. Do it while the engine is hot so it evaporates quick.
Very possible the 60 dollar amazon coil is a dud, but be sure the connectors going to it are clean and free of corrosion anyway. Check for damage to insulation here as well.
NGK Plat? Why? Turbo? If you are naturally aspirated, you should run the regular copper core plugs. I use the vpower, good plugs. Gap to 38. Ebay link, but they are available almost anywhere.