nothing unusual there, many people have had this problem

The Streak needs one with a certain power output, (1000mA) so lesser chargers aren't good enough.

Google and you'll find loads.... this one defo works, as I brought one --> http://www.blueunplugged.com/2-USB-Ports-Car-Charger.aspx#moreinfo

I had issues with 1.6. Since upgrading to 2.2 no problem.

This is the USB charger I use with the Dell cable.

http://www.belkin.com/au/IWCatProductPage.process?Product_Id=489767

Search Ebay for "Belkin Micro USB Charger"

I bought one of these today but it still doesn't work.  I can't understand why when it works to charge from the pc or mains???

Anyway, I phoned O2 (UK) as I purchased it on contract from them and told them I needed the phone as I'm a taxi driver and a phone that wont charge in the car it no use whatsoever.  They said that I should take it to one of their stores to be looked at and, if needed, they'd send it to be repaired or replaced.  I told them that it was a new handset, as the previous one had been ruined by the 2.1 OTA update in September and Dell replaced it.  

I'll see what they suggest but wont hold my breath.

The firmware update to 2.2 should fix your charging issue.