What should I look out for? Should I pull the trigger?

Hi everyone, longtime lurker here!

I'm looking at bidding on an eBay 2004 Impreza WRX with 68k miles on the clock. The seller has no service history and it's got a crappy after market bumper with a crack in it.

If I was to win it, I'd be doing a full service including the timing belt straight away with a view to replacing the bumper with an OEM one.

What should I look out for when I check the car out before bidding? Any common faults?

Thanks in advance guys, I'll post pics if I win the auction!!!