PT cruiser engine light flashing?

[Tj Walker]

2004 PT cruiser. Automatic transmission. Regular engine, no turbo. 97K miles. Last week the engine light came on (it was not blinking). Error code is P0302, which is a cylinder misfire. I found one plug wire loose and replaced it. The light went off, but the code stayed on. Today, the car began to run roughly and the engine light came back on and is now blinking. Any ideas as to what may be wrong with it? Taking to a mechanic tommorrow and dont want to get ripped off. Second question, is it safe to drive 15 miles to a mechanic or should I get it towed. Thanks