I made the terrible mistake for buying parts from Prime. These are wholesale items that have zero QC. The spark plug coils were probably the worst mistake in judgement I have made. The series of events that followed, cost hours and hours of work. I even thought the knock sensor was going out. It was one of the coils misfiring at low rpm's. Now remember when you have a slight misfire, the last thing you think is wrong is parts that are brand new. This car was new to me, I'm fixing it up for my granddaughter 16th Bday. So.... I really wasn't aware what issues were new or old, or self inflicted. The 2nd thing I recommend not not buying is the thermostat housing, for around $40. Let's think about the amount of work required for the install. I divorced some of the auto part stores years ago when they started selling lifetime parts that lasted 6 months. And, here once again, the allure of a better price fogged my judgment. Do yourself a favor. If it's not a reputable brand, ie Bosch and others, sold by reputable online dealers, rethink

 

There are a lot of bad experiences with aftermarket thermostats posted here. I think that is a part for which OEM is the only way to go. As you note, it’s a lot of labor. Best of luck getting it ready for your granddaughter.

 

The water pipe that goes from the thermostat housing to the rear of the block where the water pump lives also needs to be MINI branded from what I am hearing. Saving a few bucks on that plastic pipe (or not replacing it at all) may end up costing a headache or several.