You can buy a complete display on Lazada for 1500 , takes only 30 minutes to replace the whole unit.
Or you can send it to a shop and have them replace the film for 500 bath. Plenty on offer on Facebook marketplace.
If the child would have been in the back straped in a child seat acording to the law this would not have happend.
Going out to make a quick errand at a gasoline station and keep engine and aircon running for the litle one should not be a problem then.
if the seller is a foreigner you need him/her to go with you to the DLT or get an resident certificate from them or other proof of his adress like yellow book or workpermit with adress on it.
Copy idd card or passport from both parties.
For you the same if you not Thai ; resident certificate or yellow book or workpermit old style with adress on it.
Good luck
CBD helps me to calm down.
When i get upset or angry i take a CBD gummy and within 40 minutes i am calm again.
It worked wonders for my Ex who is Bi Polar.
Many Thai guides went to do something else during covid and have a steady income now.
So a Big shortage for guides now even when salary is 850.- per 1/2 day or 1,700.- for a full day.