I looked at small hand held vacuums in the "big city" yeterday. FYI, all 3 contenders(hand held, reasonably high quality & power, & price! no $50 & up units allowed) had 4-foot long, 1.25" dia hoses.(think you can use the house vac attachments on 'em)
In order of my store visits, they were:
1. Home Depot had a Rigid-made, 2.5 gal, 1.75 hp unit, for $30, only advantage seemed to be a 10 foot cord. No wall bracket. It had some bad reviews on the inet, most relating to blowing dust or liquids all out the back when used to vacuum them up- I don't like the sound of that. The few in-store-stock were all in smashed-up boxes. Your HD store may vary.
2. Lowe's had a "Hang-Up" by Shop Vac, 2.5 gal, 2.5? HP, wall bracket included, 6 foot cord, for $30. Looked like it should be a great little hand-held. Does *Not* look like the photo on the Lowe's website- go to the Shop Vac site to see accurate photo. Lots of 'em in stock, pristine boxes.
3. Lowe's also had the "Bucket Max" by Shop Vac, just a lid & vacuum motor head to attach to your own 5-gal plastic bucket. So good it was priceless-

- at least they had no price posted for it. I would expect ~$20 but that's a guess fueled by the SV site. Hose only, no? only 1? attachments, also 6 foot cord.
4. Walmart had a "Hang-On" by Shop Vac, 1.5 gal, 2.0 HP, 6 foot cord, also w/wall bracket, for $25. Looked like it should also be fine for a small easily used car vacuum. Also lots of 'em in stock in pristine boxes.
IMO- it's a toss-up between the $30 Lowe's 2.5 gal Hang-Up & the $25 Walmart 1.5 gal Hang-On. They have identical hoses, cord lengths, attachments, & filter systems. The extra $5 at Lowe's buys you an extra gallon of capacity & a tiny bit more powerful suction(see specs at SV site), so you pays your money & takes your choice.
I think I'm gonna buy myself one of those blue Lowe's vacs for Christmas.

Your choice may vary.