OK, I am no expert or anything, but I do have 6 SCPs in the possive range so I must be doing something right.
No, this is a safe. Euclid is when a thing is really wierd in a way that makes containing it difficult.
The Containment seems ok, save a few niggles. First, why would people be allowed in for reasons other than testing at times other than the ones it is active? Why not just say "no access save for testing"? Also, again just a niggle, but the last scentance adds nothing and even seems a little paranoid.
Put the what before the when, what is it before when it was discovered. The tone is also off, which is a difficult thing to get right. Be more clinical in the description, for example:
It has no mechanical problems except the music player doesn't work. It can be driven (fueled by a diesel engine originally made for the truck) and can reach average speeds of the same model.
SCP-XXX functions in line with expectations for this model of vehicle save for the audio system which cannot be activated deliberately and the freezer compartments which do not require an external power scource.
(I probably went a little bit too far the other way but you get the idea)
I am not sure about the repeated use of "Ice creams or frozen treats", aren't icecreams frozen treats? Or is this a left/right pondian thing?
I think concicness is an issue too, for instance I can sum up:
The person's clothes and other accessories can be found neatly folded and place on the floor of the truck. The frozen treats are found wrapped differently every time with different styles.
Through the treat will contain regular flavors (Chocolate, Strawberry, Vanilla) as advertise on the wrappings a “Special flavor” can also be found. This consists of the human that entered the vehicle the early morning before. Multiple tests have shown that the amount of the frozen substances are the exact weight of the human a and the wrapper changes every person.
After a subject has entered SCP-XXX the subjects garments are found folded in SCP-XXX and the freezer units are found to contain goods who's wrappers advertise a "special flavour". Examination of the goods reveals the presence of DNA matching the subject. The wrappers of the goods differs with each subject.
And even then, I am not sure if some of that could not be removed.
I don't think SCP-XXX-1 adds anything myself.
Test logs soon to come
Why? Just because lots of SCPs have them does not make having them nessicary. Why does your SCP need test logs? I can't see a need. If you can then fine but don't put them in just because you can.