Hobby Grades
The most collectable version
Those "Hobby Grade" features or "Added Features" are...
Digital proportional steering (variable steering), which means you can turn the transmitter wheel slightly and the car turns a little. Turn the transmitter wheel alot and the car turns alot.
Variable speed control this means you pull back on the trigger a little the car moves a little, pull back on the trigger all the way and the car takes off! This also works for reverse gear as well.
Now if this isn't cool enough...
Each "Hobby Grade" Rc car has their own dedicated frequency. ALL 6 cars 1 of EACH DIFFERENT DRIVER the series of cars you can race at the same time. WOW !
ALL Dale Earnhardt Sr HG cars is made with Frequency A is 26.995
All Tony Stewart HG cars are made with a dedicated frequency Frequency B is 27.045
ALL Jimmie Johnson HG cars are made with Frequency C is 27.095
Dale Earnhardt Jr cars (Bud Racing and "Wheat Crest" Versions ARE THE SAME FREQUENCY!
Frequency D is 27.145. These 2 cars CANNOT be raced at the same time UNLESS you have frequency "borrowed" from another Rc car listed here that you already own, OR a "Frequency Chipset" which can be purchased separately easily
ALL Michael Waltrips # 55 Napa Autoparts Toyota HG cars is made with Frequency E is 27.195
ALL Brian Vickers # 57 Ore-Ida HG cars is made with Frequency E is 27.195
ALL Jeff Gordon # 24 HG cars is made with Frequency F is 27.255
NO TWO ALIKE CARS can race together UNLESS you have the "frequency of another car chassis and transmitter" to change it, or a "Frequency 6-Pack" from www.checkerflagzone.com 
Then in theory you can run any ONE other duplicate car OR 6 IDENTICAL Hobby Grade cars (6 Tony Stewart cars or 6 Dale Jr cars etc. etc.) you can race at the same time. This makes it great for families that have several Tony Stewart fans or Dale Jr fans. This makes for alot of potential confusion AND wrecks !! But I have seen this done. You can also run a Base Version Nascar Rc car with these 6, PROVIDED it is the 49 mghz frequency. But I don't recommend this since Base Versions are difficult to control. We will get into the First Editions and Base Versions on another page.
The transmitters for the "Hobby Grades" cars are different as well. The "Hobby Grade" version transmitter has two "trim" adjustments on the back of the remote as well as the Frequency Chip on the side of the remote than can be changed and can also be changed on the chassis of the car. Below is a "Hobby Grade"transmitter. Note the two black knobs on the back of the transmitter. This also distinguishes the First Editions and Base Versions from the "Hobby Grade" Version.

Amazon.com, (the ONLY legal online retailer of Hobby Grades at the time of this posting but mistakes are being made by warehouse employees that dont know what they are doing) and other online locations Costco.com, Nascar.com QVC.com (they sell ONLY Base versions!!! Except #8 Dale Jr. "Budweiser Racing" Rc car which ONLY came out in Hobby Grade), they have to be huge production runs. Most likey in the tens of thousands and still going strong.
Not all at once mind you but I know for a fact that the other
6 Hobby Grades listed here below...
# 3 Dale Earnhardt Sr. GM Goodwrench DEI
# 8 Dale Jr. "Budweiser Racing" version DEI
# 8 Dale Jr. "DEI Wheat Crest" version DEI
# 20 Tony Stewart "Home Depot" JGR
# 24 Jeff Gordon "Dupont Racing" HMS
# 48 Jimmie Johnson "Lowes Home Improvement" HMS
...are still being produced at the time of this posting.
The original Base versions of the same drivers above are no longer being produced so as to make way for the more popular "Hobby Grade" 6th scale line of Rc cars. THEY WILL BE TOUGHER TO FIND in the future.!!
If you haven't noticed the differences in the packaging it wouldn't surprise me. Lots of people don't notice. On the following page, I will display ALL of the differences, side by side, of the "Hobby Grades" and " First and Second Edition" Base Versions. You will be amazed at the subtle differences that most people dont even see. NEW Hobby Grade boxes on the following pages!!!!