Car Rental - Driving From Zurich to Alsace

Switzerland is generally quite light on car rental offices. Renting at Zürich Airport, it might be significantly cheaper to return the car there. I think there's just Europcar and Sixt in Luzern, so shop around and see. There are direct trains from Zürich Airport to Luzern anyway.

Otherwise, parking won't be an issue in any of the places on your list; just use paid parking lots as needed and don't bother hunting for street parking.

You'll also be fine with a slightly larger car. Just make sure to follow speed limits to a T, especially in Switzerland, and notify the rental agency that you will cross the border (it will be fine, but they need to know). The border crossing itself is a seamless non-event.

regarding Swiss speed limits - yes, follow the speed limit, not "just a little over". Note that speeds are reduced in tunnels and monitored both on entry and exit. Yes, that really does mean to slow from 130 to 80 before the sign and traffic light. Keep your distance in tunnels, if there are chevrons painted on the road stay 2 apart.

Each driver needs an IDP before driving in France.

Some routes between Switzerland / France / Germany incur queues. When returning to Switzerland go through the "Have Vignette" lines.

You won't have a French Crit'Air sticker on the windscreen so you aren't allowed to drive in Strasbourg - park in a remote lot or take the train (very easy) from Colmar.

Are you sure you want to drive that distance after what I assume is an overnight flight? It's about a 2 hour drive- add time for deplaning, passport control, getting luggage and picking up the car- so at least 2 hours for all that.
I would spend that first night in Zurich then start the drive. Or take the train to Basel first and pick up car there to continue on the next day

We always book our cars thru AutoEurope.com. We typically get a small SUV which should be large enough for your needs. Do you all really need full size luggage for a week long trip?

All drivers need an IDP- get it at your local AAA.
Do your homework and learn the European road signs. Not complicated.

We stayed in Riquewihr with a car at the Best Western Schoenenburg just a short walk from the town and has onsite parking.
Driving in the area is easy. Use the large parking lots outside the towns.
We also stayed in Colmar at Le Colombier- has onsite garage and was easy to find and access.

We returned our car in Luzern- Europcar- that was a bit dicey as it was hard to find.

Thank you!! Im not too worried about the drive after the overnight flight-- I tend to have a ton of adrenaline on travel days and my sister will be able to switch off with me if needed. But good to know about getting an IDP in advance and to be extra mindful of speed limits! Im going to look into the rental places mentioned here and see what pricing options make the most sense. If it were just me, I'd prefer to take the trains and just rent the car in Colmar for the days Im there, the real purpose of the car to and from Switzerland is to try and make things feel as easy as possible for my parents....so just wanted to get a sense for whether or not driving might actually seem MORE stressful or chaotic, too.

The driving isn't bad, but parking can be a pain. It's going to be high season so the parking lots will fill up. In Colmar park near the big movie theater and walk into the city center. It's only a 10 minute walk and that's the biggest lot, and cheapest. Strasbourg is expensive to park, consider using the train station lot, which will let you take the tram to the city center.

Rent a station wagon, not an SUV. they are much more common, and a heck of a lot faster. MBZ or BMW if you can get it. You need to let them know you're going over the border.

Personally, from Zurich I'd go to Lake Constance. It's perfect in May. As fond as I am of the Alsace, Bodensee is better.