Light Peak is located about one hour northeast of Lakeview, Oregon and features the Drake Peak Lookout that can be rented in summer. (Yes, Drake Peak Lookout is on the shoulder of Light Peak and not on Drake Peak...)
Here's an unremarkable drive-up summit in the mid-Willamette Valley west of Salem.
Cole Mountain is a drive-up in the Coast Range south of Highway 26 off of Highway 53. The road is passable in any passenger car and it's a radio quiet spot.
We might call this Peterson Summit rather than Peak 1700 - it's a drive-up in the Coast Range about 20 miles north of Tillamook and 20 miles south of Cannon Beach. The road is totally "Prius-able" (passable in a passenger car).
Here's another summit in Crater Lake National Park that accessed with a cross-country hike. The easiest ridge for ascent is near the angle of repose with loose red pumice-like scree on the upper slopes, giving Red Cone its name. Although only about 2.5 miles round trip, half of the 600 feet of gain is in the last quarter mile.
Walker Mountain is a Southern Oregon summit that could be a drive-up for those with a fully capable 4x4. However, the roughest part is also the start of a decent hike and getting to that rough spot is easy with a vehicle with decent clearance. Note that there is another Walker Mountain in Oregon - this is the one near Grants Pass.
Fielder Mountain is an easy 'road' summit in Southern Oregon. With several large RF sites at the top, the road is passable in a passenger car all the way to the summit - however a gate may put you on foot for the last portion.
You can find Nugget Butte just north of Gold Hill Oregon. Use Exit 40 from I-5, head to US 99, Then up Gustaf Street to the gate. There has been local knowledge that arranged access in the past, but without permission, do not activate.
Just south of Pistol River, Oregon take the Carpenterville Road about 8 miles south. This summit is posted "No Trespassing" except for members of the Southern Curry Dirt Riders Association.
Update February 2021 - Lost Dog Road is now gated with no motorized vehicles allowed. It's only a one mile road walk to the AZ.
This is a very much out of the way summit, along Highway 101 on the Oregon Coast, about 14 miles north of Bandon. Note that there are other Peak 740 in Oregon - make sure this one is your intended peak.