Snap-On sells automotive scopes.
https://www.snapon.com/EN/US/Diagnostics/Products/TRITON-D10
https://www.snapon.com/EN/US/Diagnostics/Products/TRITON-D10
It’s slow but it’s an oscilloscope. It graphs electrical measurements over time. They sold CRT scopes on carts for years and years.
Maybe you should move the goalposts and demand FFT or higher bandwidth.