H8 should have a vent - is there place on the either side of the battery that you might need to puncture, perhaps? You need to vent the battery, as the battery is inside the car, and even "sealed" batteries may create fumes... if the battery has "plugged" side holes that are not vented, your battery may explode due to pressure build up...

also, it seems that a lot of "new" batteries have issues directly from the factory - once installed, drive around and make sure that the battery holds its end of the bargain, the voltage is not dropping, the charging is done ok... i just had to return a spanking brand new batery back to the store after 30 days of using it - it was defective on the inside... few years back i had similar issue - then it was the 3rd battery that worked fine, while the first 2 were DOA...

i don't have the E70, can't tell you much about registration process...