As noted above Motorhome Magazine and the FMCA magazine each give an annual update on towable cars. But as a precaution, if you are purchasing new, make sure you look at the owners guide for the car to make sure that model is flat towable. Also, it has been suggested in the past to have the dealer note on the purchase transaction that you are purchasing "because the car is flat towable", that way if the manufacturer changes the standards mid-year you have some recourse. Additionally, if you have the time and inclination, you can post the type of car you are deciding on in this forum and you will surely get opinions.
Oops: I just re-read your post. When you say the owners manual says less than 5000lbs, that probably means the hitch is rated at 5000lbs. If it is a gas engine MH, like mine, then you need to check the GVCW (gross vehicle combined weight) limit and subtract the actual weight of your loaded motorhome. Take it to a scale with a full tank of gas and propane (water depends on whether you travel full or empty) and food and clothing and add passenger weight. The difference may be greater than you think and 5000lb is no longer within limits. I figure my limit to be approx. 4000lbs will a normal load. My Saturn weighs in at 3970 with luggage in tow. I also have a supplemental brake on the towed car.
Happy Trails
