There are still occasional checks around the Geneva / France border to check your purchases. They just seem random. Sometimes they are there, sometimes they aren't. Locals tell me they are out in weekends when people shop.

There are also city buses that cross the border without stopping unless they randomly get stopped. The trains from France come into a particular platform at Cornavin train station where they can see people exit and talk to anyone carrying a lot of stuff.

The rules and process is confusing to a non-local like me but pretty low hassle in the end.

It's been over a decade and I didn't drive while we were there but I remember it looking a lot like a tollbooth in the US, but one with military/police looking people that would randomly, or not so randomly, select people to pull off to the side so that they could search your vehicle. At least one time when we crossed into France to go grocery shopping we were searched and had to show our passports and they looked through our groceries and asked to see the receipt.