Small
Seep of coolant left top ,think it could be from the small pipe that is in the rad under the air intake,it's a bug wrx. Are these prone to trouble
The top inlet end tanks give problems due to it being the side where the hot coolant enters. I would'nt try and repair the plastic as it tends to go where there is a tiny join line and will only split again. Mine did the same recently but I'd a spare off the type R lying round. Alloy ones are an option but don't buy a cheap chinese one. RCM run a standard OEM one in the Gobstopper and apparently they are perfect for the job, even with an engine running 800+ BHP.