To get "highly compressed" Need for Speed (NFS) PS2 ISOs that actually work, your best bet is converting your own files into the CHD (Compressed Hunks of Data) or GZ (Gzip) formats.
9 (Maximum compression, but slower decompression).CHD (Compressed Hunks of Data): This is the current gold standard for PS2 emulation. It offers a 30%–60% reduction in size and is lossless, meaning no data is deleted. You can convert ISOs to CHD using a tool called chdman. Need For Speed Ps2 Iso Highly Compressed