Searching for this keyword will lead you to dangerous websites. Here is how to stay safe:
My Summer Car is a PC-exclusive game developed by Amistech. It has never been released for the Sony PlayStation Portable (PSP). Therefore, you cannot play the authentic, original My Summer Car on any PSP console or the PPSSPP emulator.
You can find files on obscure forums, but they are unstable, lack the core "building the Satsuma" experience, and often crash on PPSSPP versions 1.14 and above.