So i change my girls oil, ive been doing it every 3 months since weve been together for the past five years without incident. Two days ago my girl asked me at 5pm if we could do her nieces oil (Chevy Cruze). I had been offering for awhile but she asked me late at night before id ever even looked under the hood. I used to work at a Chevy, Buick an GMC dealership but i worked on the Buick an Gmc side. Anyways i said yes and she drove her sisters car from euless tx to fort worth tx to our house. Thats when she tells me that her neice is going to drive the car to Austin Tx the next day or the day after. That makes me uneasy since ive never worked on this car. Oil changes are as easy a thing as can be but different cars require different parts like the Oil Filter Cap socket size for example (which was a different size then my truck or my girls car) so we got the part and proceeded to do the oil change. First thing i notice is theres oil all over the top of the engine but it looks dry and ive never seen the car and my girl acts as if its normal so i make a note to make sure the oil cap goes back on well. So next thing, the drain plug isnt stock and the gasket under it is chewed up and shredded to hell and i send a picture to her niece to make sure she knows we need to get a new one ASAP. So i finish draining the oil then put the new filter in the filter cap and screw it back in nice and snug but not as tight as it was before i took it off cause the mechanic probably used way too much torque. But it know it was sealed well. The drain plug was put back on but this time tighter cause it was literally so loose i could turn it with my hand when i was taking it off the first time. It doesnt need to be super tight but certainly tighter than it was. We refill the oil, i pour in the exact 4.0 liters (4.25 quarts) the manual specifies. The job is done so i replace the oil cap and double checked it was on correctly. After which my girl asks me if i remembered to which i tell her yes but just for peace of mind i do it again in front of her. Then i close the hood and gently drive the car off of the ramps i had it on(the cars front is so low that i didnt want the shocks to load from the force and lower the front into the ramps damaging the car) so going slowly was the correct course of action. Next we drive the car to my dogs vet to pick up a prescription and then continue on to Euless to drop off the car and get my girls car. Her nieces car needed more anti freeze but the car was too hot to change it and we had to go so i had the idea to make a video for her niece and her boyfriend showing them how to change it. It turned out good actually, maybe even youtube worthy lol. Anyways so that was it. Job well done i thought. Today i get a message that her nieces check engine light had turned on. So i ask her neice to call asap. Then i walk her through sending me pics of the car, dipstick level etc. THERES NO OIL IN THE CAR and oil is all over the top of the engine. I look it up and it turns out theres a bulletin for Chevy Cruzes about the oil cap being easy to misalign. I told her that she would have to put in more oil and that it would be smart to put some Vaseline around the cap after just in case its still trying to leak. She was only able to put in 2 quarts but thats better then zero i just told her to pull over the second she notices any trouble. Im posting this cause i take things like this very hard. Should i have noticed the cap rather then assuming that since there hadn't been an incident that the cap must be fine(i mean the oil wasn't wet that was on the top of the engine so i thought it couldn't be new). Anyways im not really questioning the job i did. Im just questioning why the fuck the universe couldn't let me have just this one little win. It feels great to help people out, but it feels terrible when an attempt at a kind gesture turns into an enormous inconvenience for the person receiving the gesture. Her nice is really sweet and said things like its ok "no worries' and even my girlfriend who doesn't always have my back is telling me its ok not to worry about it. I just hate knowing they possibly don't know enough about the situation or cars to know if what i did had anything to do with this or not. I know that in all likelihood the cars oil cap was already bad and taking it on and off a few times is what made it worse. And because i know that they dont understand it likely wasn't my fault i feel the same as i would if this were actually 100% my fault. Anyways, i realize this is a stupid place to post this but i needed to vent. This is long enough i doubt anyone will read it but again, just wanted to vent a little.