Well even though its a small car remember it was designed to haul 4 adults at say 150lbs each so if its just you you could carry 450lbs there. Also it was intended to haul something like 50-100lbs in the trunk. Do cars have a sticker in the door like trucks, even small trucks like my s-10 have a sticker listing the vehicle weight and payload. They are disguised as GWVR and such, just search for the terms you read there. To help insure safety you can do a few things. First of all is drive safely. Second buy decent tires, they have weight, speed, temperature (as you drive tires make heat), traction and wear ratings, make sure to exceed the OEM tires (not hard to do) when buying. Keep your vehicle maintained, check your brakes, rotate your tires which is very important on a front wheel drive like yours as they are harder on tires. Keep the windows clean so you can see, washer fluid is cheap, buy in bulk if you must. When you replace things like your brakes, go for good quality instead of whatever is cheapest at the store (I recommend raybestos, first time I ever tried them I would have ate steering wheel if not for the seat belt the difference was that much). Make sure the stuff you carry is fastened down well. Some cars have seats that fold down and even in the ones that don't have fold down seats its just a bit of fabric and foam that separates the trunk from you and tools and supplied could easily tear through in a wreck or panic stop.